U.S. patent application number 11/452182 was filed with the patent office on 2007-12-13 for suspended ceiling system.
Invention is credited to Randall S. Pratt.
Application Number | 20070283657 11/452182 |
Document ID | / |
Family ID | 38820484 |
Filed Date | 2007-12-13 |
United States Patent
Application |
20070283657 |
Kind Code |
A1 |
Pratt; Randall S. |
December 13, 2007 |
Suspended ceiling system
Abstract
A suspended ceiling system having a plurality of elongated
ceiling panels each of which has a planar web section and rail
portions extending along opposite side edges of the web section, a
pair of channel-shaped wall mounts mounted on the opposed walls of
a room, and having an upper laterally extending flange and a lower
laterally extending flange on which one end of a ceiling panel
rests. The ceiling panels are held in place by Z-shaped retainer
clips which snap in between the upper and lower flanges of the wall
supports at locations between the ceiling panel rails. Each clip
has an upper horizontal leg extending inwardly and a lower
horizontal leg extending outwardly. Each of the horizontal legs
bear against a surface of a web section of a ceiling panel. The
horizontal legs are connected by a diagonal leg which extends from
the upper horizontal leg at the wall support to the lower
horizontal leg away from the wall support. The diagonal leg clamps
the horizontal legs against the upper and lower flanges of the wall
support.
Inventors: |
Pratt; Randall S.; (Hudson,
NH) |
Correspondence
Address: |
Jacobs Patent Office
P.O. Box 390438
Cambridge
MA
02139
US
|
Family ID: |
38820484 |
Appl. No.: |
11/452182 |
Filed: |
June 13, 2006 |
Current U.S.
Class: |
52/506.08 |
Current CPC
Class: |
E04B 9/242 20130101;
E04B 2103/06 20130101; E04B 9/30 20130101; E04B 9/067 20130101 |
Class at
Publication: |
52/506.08 |
International
Class: |
E04B 9/06 20060101
E04B009/06 |
Claims
1. A suspended ceiling system for an enclosure having opposed walls
comprising: a plurality of elongated ceiling panels including a
planar web section having opposed inner and outer surfaces
respectively facing toward and away from the interior of the
enclosure, opposed side edges, opposed end portions and a rail
portion extending upwardly from and longitudinally along each of
said side edges; a pair of generally channel-shaped wall supports
adapted to be mounted on opposed walls of a room, each of said wall
supports including a vertical leg adapted to be mounted against a
wall, an upper flange extending laterally inwardly from an upper
portion of said vertical leg and a lower flange extending laterally
inwardly from a lower portion of said vertical leg, said upper and
lower flanges being spaced apart a sufficient distance for one end
portion of a plurality of said ceiling panels, disposed side by
side with the rail portions of adjacent panels abutting, to fit
there between and rest on said lower flange; and at least one
Z-shaped retainer clip for each end of a ceiling panel, each of the
retainer clips having (i) an upper leg extending laterally inwardly
and adapted to fit against the underside of the upper flange of the
wall support, (ii) a lower leg extending laterally outwardly and
adapted to fit against the outer surface of the web section of said
ceiling panel resting on the lower flange of said wall support, and
(iii) a diagonal leg extending diagonally inwardly from the upper
leg at about the wall support to the lower leg; the outside
dimension of the upper and lower legs of said Z-shaped retainer
clip approximating the inside dimension between upper and lower
flanges of said wall support minus the thickness of the web section
of said ceiling panel, whereby said Z-shaped retainer clip fits
between the upper and lower flanges of the wall support with the
upper leg bearing against the upper flange of said wall support
member and the lower leg bearing against and clamping the web
section against the lower flange of said wall support to retain
said web section from being pushed or pried away such lower
flange.
2. The ceiling system of claim 1 wherein the Z-shaped retainer clip
has a height less than, but corresponding to at least a major
portion of, the distance between the rail portions on each ceiling
panel so that one of said retainer clips restrains substantially
the entire width of the web section.
3. The ceiling system of claim 1 wherein the upper flange of the
wall support and the upper leg of the retainer clip have a width
substantially less than the width of the respective lower flange of
the wall support and lower leg of the retainer clip so as to
facilitate installation of the retainer clip.
4. The ceiling system of claim 1 wherein each of said rail portions
include a side wall extending upwardly from and longitudinally
along the respective side edge portion of said web section; and an
in-turned flange extending laterally inwardly from said side wall
portion, whereby when a plurality of said ceiling panels are
installed side by side, the side wall portions of adjacent ceiling
panels abut.
5. The ceiling system of claim 4 further including auxiliary
retainer clips for installation at the joints between adjacent
ceiling panels.
6. The ceiling system of claim 1 further comprising at least one
generally inverted T-shaped intermediate support member adapted to
be supported from an overhead support and extending generally
parallel to and spaced from an opposed pair of said wall supports,
said intermediate support member including a vertical leg, first
and second upper flanges extending laterally outwardly in opposite
directions from an upper portion of said vertical leg and first and
second lower flanges extending laterally outwardly in opposite
directions from a lower portion of said vertical leg; the first
upper and lower flanges of said intermediate support member being
spaced apart a sufficient distance for one end portion of a first
group of a plurality of said ceiling panels, disposed side by side
with the rail portions of adjacent ceiling panels abutting, to fit
between said first upper and lower flanges and rest on said first
lower flange; the second upper and lower flanges of said
intermediate support member being spaced apart a sufficient
distance for one end of a second group of a plurality of said
ceiling panels, disposed side by side with respect to each other
and with the rail portions of adjacent panels abutting and disposed
end to end with respect to the first group, to fit between said
second upper and lower flanges and rest on said second lower
flange; and a Z-shaped retainer clip for each of said ceiling
panels adapted to fit between the first and second upper and lower
flanges of said intermediate support member.
7. The ceiling system of claim 6 wherein the Z-shaped retainer clip
has a height less than, but corresponding to at least a major
portion of, the distance between the rail portions for each ceiling
panel so only one of said clips restrains substantially the entire
width of said web section.
8. The ceiling system of claim 7 wherein the first and second upper
flanges of said intermediate support member and the upper leg of
each Z-shaped retainer clip has a width substantially less than the
width of the respective first and second lower flanges of said
intermediate support member and said leg of each Z-shaped retainer
clip.
9. A building which comprises a suspended ceiling system for an
enclosure having opposed walls comprising: a plurality of elongated
ceiling panels including a planar web section having opposed inner
and outer surfaces respectively facing toward and away from the
interior of the enclosure, opposed side edges, opposed end portions
and a rail portion extending upwardly from and longitudinally along
each of said side edges; a pair of generally channel-shaped wall
supports adapted to be mounted on opposed walls of a room, each of
said wall supports including a vertical leg adapted to be mounted
against a wall, an upper flange extending laterally inwardly from
an upper portion of said vertical leg and a lower flange extending
laterally inwardly from a lower portion of said vertical leg, said
upper and lower flanges being spaced apart a sufficient distance
for one end portion of a plurality of said ceiling panels, disposed
side by side with the rail portions of adjacent panels abutting, to
fit there between and rest on said lower flange; and at least one
Z-shaped retainer clip for each end of a ceiling panel, each of the
retainer clips having (i) an upper leg extending laterally inwardly
and adapted to fit against the underside of the upper flange of the
wall support, (ii) a lower leg extending laterally outwardly and
adapted to fit against the outer surface of the web section of said
ceiling panel resting on the lower flange of said wall support, and
(iii) a diagonal leg extending diagonally inwardly from the upper
leg at about the wall support to the lower leg; the outside
dimension of the upper and lower legs of said Z-shaped retainer
clip approximating the inside dimension between upper and lower
flanges of said wall support minus the thickness of the web section
of said ceiling panel, whereby said Z-shaped retainer clip fits
between the upper and lower flanges of the wall support with the
upper leg bearing against the upper flange of said wall support
member and the lower leg bearing against and clamping the web
section against the lower flange of said wall support to retain
said web section from being pushed or pried away such lower
flange.
10. The building of claim 9 wherein the Z-shaped retainer clip has
a height less than, but corresponding to at least a major portion
of, the distance between the rail portions on each ceiling panel so
that one of said retainer clips restrains substantially the entire
width of the web section.
11. The building of claim 9 wherein the upper flange of the wall
support and the upper leg of the retainer clip have a width
substantially less than the width of the respective lower flange of
the wall support and lower leg of the retainer clip so as to
facilitate installation of the retainer clip.
12. The building of claim 9 wherein each of said rail portions
include a side wall extending upwardly from and longitudinally
along the respective side edge portion of said web section; and an
in-turned flange extending laterally inwardly from said side wall
portion, whereby when a plurality of said ceiling panels are
installed side by side, the side wall portions of adjacent ceiling
panels abut.
13. The building of claim 12 further including auxiliary retainer
clips for installation at the joints between adjacent ceiling
panels.
14. The building of claim 9 further comprising at least one
generally inverted T-shaped intermediate support member adapted to
be supported from an overhead support and extending generally
parallel to and spaced from an opposed pair of said wall supports,
said intermediate support member including a vertical leg, first
and second upper flanges extending laterally outwardly in opposite
directions from an upper portion of said vertical leg and first and
second lower flanges extending laterally outwardly in opposite
directions from a lower portion of said vertical leg; the first
upper and lower flanges of said intermediate support member being
spaced apart a sufficient distance for one end portion of a first
group of a plurality of said ceiling panels, disposed side by side
with the rail portions of adjacent ceiling panels abutting, to fit
between said first upper and lower flanges and rest on said first
lower flange; the second upper and lower flanges of said
intermediate support member being spaced apart a sufficient
distance for one end of a second group of a plurality of said
ceiling panels, disposed side by side with respect to each other
and with the rail portions of adjacent panels abutting and disposed
end to end with respect to the first group, to fit between said
second upper and lower flanges and rest on said second lower
flange; and a Z-shaped retainer clip for each of said ceiling
panels adapted to fit between the first and second upper and lower
flanges of said intermediate support member.
15. The building of claim 14 wherein the Z-shaped retainer clip has
a height less than, but corresponding to at least a major portion
of, the distance between the rail portions for each ceiling panel
so only one of said clips restrains substantially the entire width
of said web section.
16. The building of claim 15 wherein the first and second upper
flanges of said intermediate support member and the upper leg of
each Z-shaped retainer clip has a width substantially less than the
width of the respective first and second lower flanges of said
intermediate support member and said leg of each Z-shaped retainer
clip.
17. The building of claim 9 wherein the suspended ceiling system is
inside.
18. The building of claim 9 wherein the suspended ceiling system is
outside.
19. The building of claim 18 wherein the building is a tunnel.
Description
BACKGROUND OF THE INVENTION
[0001] This invention relates to suspended ceiling systems
including a plurality of ceiling panels supported on wall mounted
supports and optionally intermediate tee supports suspended from an
overhead support. More particularly, this invention relates to
suspended ceiling systems for use in correctional institutions and
other applications requiring ceiling panels to have superior hold
down resistance. This invention also relates to suspended ceiling
systems for use in architectural ceiling systems, particularly in
areas possibly subject to high wind uplift such as a tunnel.
[0002] Suspended ceiling systems typically include a plurality of
rectangular metal ceiling panels including a planar web section,
which is either solid or perforated, and side rails having a side
wall extending upwardly from and along the length of the opposite
edges of the web section. The opposite ends of the ceiling panels
are supported on a flange of supports mounted on the opposite walls
of a room. For larger rooms requiring ceiling panels end to end,
one end or both ends of some ceiling panels are supported on the
flanges of intermediate tee supports suspended from ceiling joist
or similar overhead support. Primarily for security purposes, it is
desirable for the ceiling support arrangement to be such that the
ceiling panels cannot be removed, except for an access panel
requiring special tools, and so that the ends of the ceiling panels
cannot be pushed or pried away from supporting flanges of the
wall-mounted supports or intermediate tee supports far enough for a
prisoner to hide contraband, such as razor blades, drugs, or the
like.
[0003] In one type prior security ceiling system, opposite ends of
ceiling panels are fastened to both upper and lower flanges on
wall-mounted supports and tee supports by tamper-proof metal
screws. Installation of this type ceiling system is labor intensive
and the heads of the screws for the lower flanges are visible and
detract from the aesthetic appearance of the completed assembly.
The fasteners also potentially provide an exposed avenue of
attempted ceiling system breech.
[0004] In another type prior security ceiling system, wall mounts
include a first angle fixture anchored into the wall on which the
security panels rest and a second angle fixture anchored in the
wall above the first angle and bearing against the top edges of the
ceiling panel rails to restrain upward movement of the ceiling
panels. The installation of this type security ceiling system also
is labor intensive.
[0005] In still another type of prior security ceiling system, wall
mounts and intermediate tee supports are extruded aluminum parts.
The wall mounts are L-shaped and include a laterally extending
support flange and guide-ways formed in the vertical part and the
tee supports have a similar configuration. The ceiling panels are
clamped against the support flanges of the wall mounts and tee
support by extruded aluminum clamping members having a portion
arranged to be received in the guide-ways. In addition to the cost
associated with extruding the wall angles, tee supports and
clamping members, the installation of this type system also can be
labor intensive.
[0006] U.S. Pat. No. 5,263,295 seeks to overcome the problems
explained above by the use of a "channel" or C-shaped retainer clip
to hold the security panels in place within the flanges. While the
C-shaped retainer clip does reduce the labor requirements for an
installation, it has been found not to be sufficiently strong to
completely prevent access to the ceiling area from strong
individuals, or a strong external load such as a wind uplift. The
present invention overcomes this weakness by producing a system
which can withstand a force about more than 5 times that of the
C-shaped retainer clip.
[0007] A primary object of this invention is to provide a suspended
ceiling system including a mounting arrangement which is simply
constructed, convenient to install, and substantially stronger than
prior screw-less ceiling systems.
[0008] Another object of the invention is to provide such a ceiling
system in which the mounting arrangement positively clamps
substantially the entire width of the web section of the ceiling
panels against support flanges on the wall supports and also the
tee supports if used.
[0009] Another object is to provide an improved suspended ceiling
systems for use in correctional institutions and other applications
requiring tamper proof ceiling panels.
[0010] A further object is to provide an improved suspended ceiling
system for use or use in architectural ceiling systems which may be
subject to possible high wind uplift, e.g. tunnels.
[0011] These and other objects, aspects and advantages of the
invention will become apparent to those skilled in the art upon
reviewing the following detailed description, the drawings, and the
appended claims.
SUMMARY OF THE INVENTION
[0012] The invention provides a suspended ceiling system for an
enclosure, such as a prison, jail cell or tunnel, including a
plurality of elongated ceiling panels having a planar web section
and rail portions extending upwardly and longitudinally along each
of the opposite side edges of the web section and a pair of
generally channel-shaped wall supports adapted to be mounted on
opposed walls of the enclosure. Each wall support has a vertical
leg adapted to be mounted against a wall, an upper flange extending
laterally inwardly from the upper portion of the vertical leg and a
lower flange which extends laterally inwardly from a lower portion
of the vertical leg and on which one end of the ceiling panels
rests.
[0013] Generally inverted T-shaped intermediate supports are
provided for enclosures requiring two or more ceiling panels end to
end. The intermediate supports are supported from an overhead
support and extend generally parallel to and spaced from an opposed
pair of the wall supports. They include a vertical leg, first and
second upper flanges extending laterally outwardly in opposite
directions from an upper portion of the vertical leg and first and
second upper flanges extending laterally outwardly in opposite
directions from the lower portion of the vertical leg. A first
group of a plurality of the ceiling panels, disposed side by side
with respect to each other and with the rail portions of adjacent
ceiling panels abutting, rest on the lower flanges of an
intermediate support and a plurality of ceiling panels, disposed
side by side with respect to each other and with the rail portions
of adjacent panels abutting and disposed end to end with respect to
the first group, rest on the other lower flange of an intermediate
support.
[0014] The present invention is particularly directed to ceiling
systems incorporating a Z-shaped retainer clip used to hold ceiling
panels in place. The Z-shaped retainer clips snap in between the
upper and lower flanges of the wall supports at locations between
the ceiling panel rails. Each Z-shaped retainer clip has an upper
horizontal leg and an lower horizontal leg each of which bear
against a surface of the web sections of the ceiling panels and a
diagonal leg which extends between the lower and upper horizontal
legs and clamps those legs against the upper and lower flanges of
the wall support. The upper horizontal leg extends laterally
inwardly and the lower horizontal leg extends laterally outwardly
so that the diagonal leg extends from the upper horizontal leg at
about the wall support to about the end of the lower horizontal leg
which is most distant from the wall support and clamps the
horizontal legs against the upper and lower flanges of the wall
support.
[0015] The Z-shaped retainer clip includes (I) a diagonal leg, (ii)
a horizontal upper leg extending from the diagonal leg and adapted
to fit against the underside of an upper flange of a wall support
or an intermediate support (when used), (iii) a horizontal lower
leg extending from the diagonal leg in a direction opposite to the
direction of the horizontal upper leg and adapted to fit against
the top surface of the web section of a ceiling panel resting on a
lower flange of the wall support or intermediate support (when
used), wherein the diagonal leg attaches to the horizontal upper
leg at or about the wall support or intermediate support. The
outside dimensions of the horizontal upper and lower legs of the
Z-shaped retainer clip approximates the inside dimensions of the
upper and lower flanges of the wall supports and intermediate
supports, minus the thickness of the web section so that the
Z-shaped retainer clips will fit and re-strain the web section from
being pushed or pried up from the lower flanges.
[0016] The Z-shaped retainer clip has a height less than, but
corresponding to at least a major portion of, the distance between
the rail portions of each ceiling panel so that one clip restrains
substantially the entire width of the web section.
[0017] The upper flanges of the wall supports and the intermediate
supports preferably are narrower than the respective lower flanges
and the upper horizontal leg of the Z-shaped retainer clips is
generally narrower than the lower horizontal leg to facilitate
installation of the Z-shaped retainer clips.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] FIG. 1 is a fragmentary, perspective view (from above) of a
suspended ceiling system incorporating various features of the
invention.
[0019] FIG. 2 is a sectional view taken generally along 2-2 in FIG.
1.
[0020] FIG. 3 is an exploded, sectional and partially fragmentary
view of a wall mount with a ceiling in place prior to installation
of a retainer clip.
[0021] FIG. 4 is a sectional view taken generally along 4-4 in FIG.
1.
[0022] PRIOR ART FIGS. A-1, A-2, and A-3 are side views of,
respectively, a flanged wall support, a prior art C-shaped retainer
clip, and the prior art C-clip within the flanged ceiling wall
support as evaluated in Comparative Example A.
[0023] FIGS. 5a, 5b and 5c are side views of, respectively, a
flanged wall support, a Z-shaped retainer clip of the present
invention, and a Z-shaped retainer clip within a flanged ceiling
wall support as evaluated in Example 1.
[0024] FIG. 6 is a side view of a Z-shaped retainer clip within a
flanged ceiling wall support further including a metal shim.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0025] FIG. 1 illustrates a suspended ceiling system 10 for use in
an enclosure or room, such as a prison or jail cell, or in a space
subject to high wind uplift, such as a tunnel. The ceiling system
10 includes a plurality of rectangular ceiling panels 12,
channel-spaced wall supports 14 (one shown) mounted on opposed
walls 16 (one shown) and, when the dimensions of an area are such
to require two or more ceiling panels end to end, a plurality of
generally inverted T-shaped intermediate supports 18 extending
parallel to an opposed pair of wall supports 16.
[0026] The ceiling panels 12, preferably brake formed, rolled or
otherwise formed from a sheet metal such as steel, include an
elongated planar web section 20, which can be solid or perforated,
has an inner surface 22 facing the interior of the cell and an
outer surface 24, and side rails 26 extending upwardly from and
along the length of the opposite side edges of the web section 20.
The ceiling panels 12 typically can be up to 15 feet and even
longer when heavier sheet materials are used. For many applications
a single ceiling panel 12 can span the width or length of a room or
space and intermediate supports 18 are not required.
[0027] In the specific embodiment illustrated in FIG. 1, each of
the side rails 26 has a vertically extending side wall 28 and an
in-turned flange 30 extending laterally inwardly from the top
portion of the side wall 28. If desired, the internal flanges 30
can be omitted.
[0028] The wall supports 14, preferably brake formed, rolled or
otherwise formed from a sheet metal such as steel, include a
vertical wall or leg 32, which are each mounted against a wall 16
by a plurality of bolts 34 anchored in the wall 16 or other
suitable fastening means, an upper flange 36 extending laterally
inwardly from the upper portion of the vertical leg 32 and a lower
flange 38 extending laterally inward from the lower portion of the
vertical leg 32. The wall mounts 14 typically are preferably
approximately 10 feet long and are located on the walls 16 so that
the lower flanges 36 are at the desired height of the ceiling. The
upper and lower flanges 36 and 38 are spaced apart a sufficient
distance for one end portion of a plurality of ceiling panels 10,
disposed side by side with the side rails 26 of adjacent ceiling
panels 10 abutting, to fit there between with the web sections 20
resting on the lower flange 36, as illustrated in FIG. 1.
[0029] The intermediate supports 18, preferably brake formed,
rolled or otherwise made from a sheet metal such as steel, include
a vertical leg 40, a pair of upper flanges 42 and 44 extending
laterally in opposite directions from the upper portion of the
vertical leg 40, and a pair of lower flanges 46 and 48 extending
laterally in opposite directions from the lower portion of the
vertical leg 40. The intermediate supports 18 are suspended from
ceiling joists or other similar supports (not shown) by hangers or
the like (not shown) and extend parallel to an opposed pair of wall
supports 14. The intermediate supports 18 are spaced from each
other and from a wall support 14 so that the distance between the
vertical legs 40 of adjacent intermediate supports 18 and the
distance between the vertical legs 32 of the wall supports 14 and
the vertical legs of the intermediate supports 18 approximates, but
is slightly greater than, the length of the ceiling panels 12.
[0030] The upper and lower flanges 42 and 46 extend from one side
of the vertical leg 40 of each intermediate support 18 and are
spaced apart a sufficient distance for one end portion of a first
group X of the ceiling panels 12, disposed side by side with the
side rails 26 of adjacent ceiling panels 12 abutting, to fit there
between with the web sections 20 resting on the lower flange
46.
[0031] The upper and lower flanges 44 and 48 extend in the opposite
direction (from flanges 42 and 46) from the vertical leg 40 and are
spaced apart a sufficient distance for one end of a second group Y
of ceiling panels 12, disposed side by side with respect to each
other and end to end with respect to the first group X, to fit
there between with the web sections resting on the lower flange 48
as illustrated in FIG. 1.
[0032] In the preferred construction illustrated, the intermediate
supports 18 are similar to a pair of wall supports 14 which have
been fastened together back to back by welding or the like, thereby
reducing fabrication costs.
[0033] The ceiling panels 12 are held in place against the lower
flanges 38 of the wall supports 14 by Z-shaped retainer clips 50
which have (I) a diagonal leg 52 extending diagonally between (ii)
a horizontal inwardly extending upper leg 54 adapted to fit against
the underside of the upper flange 36 of a wall support 14 and (iii)
a horizontal outwardly extending lower leg 56 adapted to fit
against the upper surface 24 of the web section 20 of a ceiling
panel 12 as best illustrated in FIG. 2.
[0034] Referring to FIG. 3, the outside dimension A of the upper
and lower legs 54 and 56 of the retainer clips 50 approximates the
inside dimension B between the upper and lower flanges 36 and 38 of
a wall support 14, minus the thickness of the web section 20 of the
ceiling panels 12, so that there is a tight enough fit between the
lower leg 56 of the retainer clip 50 and the web section 50 to
prevent the ceiling panels 12 from being pushed or pried away from
the lower flange 38 of the wall mount 14. Generally, the wall
supports 14 and the intermediate supports 18 are formed from 12
gauge steel, the retainer clips 50 from 14 gauge steel. Thus
dimension A is about 3.5 inches and dimension B is about 3.25
inches when the ceiling panels 12 are formed from 16 gauge
steel.
[0035] While two or more Z-shaped retainer clips 50 can be used to
hold each end of a ceiling panel 12 in place, they should have a
total length corresponding to at least a majority of the width of
the web section 20 of the ceiling panel 12. Preferably however, a
single retainer clip is used at each end and each such clips is
preferably at least 70%, and more preferably at least 80%, of the
width of the web section being held in place. The use of a single
retainer clip 50 to restrain substantially the entire width of a
web section 20 provides improved resistance to the section being
pushed or pried away from the lower flange 38 of the wall mounts
14. For example, when the inside width of the web section 20 is 12
inches, the retainer clips 50 can be about 9.5 inches long, and
when the inside width is 18 inches, the retainer clips can be about
15.5 inches long.
[0036] As best shown in FIG. 4, the ceiling panels 12 are held
against the lower flanges 46 and 48 of the intermediate supports 18
by retainer clips 50a closely similar to or exactly like those
described above. That is, they preferably are brake formed, rolled
or otherwise formed from a sheet metal such as steel (e.g., 14
gauge steel), the inside dimension between the upper flanges 42 and
44 and the lower flanges 46 and 48 of the intermediate supports 18
is the same B for the wall supports 14 and the outside dimension of
the upper and lower legs 58 and 60 of the retainer clips 50a is the
same A for the wall support retainer clips 50.
[0037] As best illustrated in FIGS. 2 and 3, the upper flange 56 of
the wall support 14 preferably is somewhat narrower than the lower
flange 38 and the upper leg 54 of the retainer clips 50 preferably
also is narrower than the lower leg 56. This facilitates
installation of the retainer clips 50 after the ceiling panels 12
have been laid in place. As a general guide, the width of the upper
and lower flanges 36 and 38 of the wall supports 14 can be about
1-1.25 inches and about 1.75-2 inches, respectively, and the width
of the upper and lower legs 54 and 56 of the Z-shaped retainer
clips 50 can be about 0.875 inches and 1.5 inches, respectively.
For overall aesthetic appearance, the lower flanges 46 and 48 of
the intermediate supports 18 preferably are somewhat narrower than
the lower flange 38 of the wall supports 14 so that the total width
of the lower flanges 46 and 49 of the intermediate supports 18 is
less than twice the width of a wall support flanges 38. Otherwise,
the dimensional relationship of the flanges of the intermediate
supports 18 and the retainer clips 50a can be the same as discussed
above.
[0038] The Z-shaped retaining clips provide substantially improved
security over prior art C-shaped clips. For most applications,
adequate protection is provided by use of the Z-shaped retainer
clips 50 and 50a alone. For other applications requiring more
security, additional means for restraining the ceiling panels 12
from being pushed or pried away from the lower flanges of the wall
supports and the intermediate supports can be provided.
[0039] As illustrated in FIG. 1, one or more conventional barbed,
U-shaped metal fasteners 61 can be tapped on over the edges of the
adjoining upper flange 36 of the wall supports 14 and the upper leg
54 of the retainer clips 50 to further secure the retainer clips 50
in place. Similar fasteners can be used with the upper flanges of
the intermediate supports 18 and the retainer clips 50a.
[0040] In the event some space exists between a ceiling panel web
section 20 and the lower flange 38 of a wall support 14 or a lower
flange 46, 48, of an intermediate support 18 after installation,
e.g., because of a build up of manufacturing tolerances, thin metal
shims 74 can be driven between the top surface 24 of the web
section 20 and those lower flanges as illustrated in FIG. 6. As a
further safety precaution, the side rails 26, of adjacent ceiling
panels 12 can be fastened together with metal screws 76 or other
suitable fasteners as illustrated in FIG. 1.
COMPARATIVE EXAMPLE A
[0041] The amount of force required for an individual to gain entry
to the space above a conventional metal ceiling held in place
within a wall support by a prior art C-shaped ceiling retainer clip
was determined. A C-shaped retainer clip made of 14 gauge steel was
evaluated. The horizontal upper leg extended 0.875 inches, the
vertical leg was 3.25 inches high, and the horizontal lower leg
extended 1.5 inches. The C-shaped retainer clip 100 and its
placement within a wall support 14 above a metal ceiling panel 12
are shown schematically in PRIOR ART FIGS. A-1, A-2, and A-3.
[0042] The governing performance failure mode was bending of the
bottom leg and the load required was 173 pounds.
EXAMPLE 1
[0043] The procedure of Comparative Example A was repeated with a
14-gauge steel Z-shaped retainer clip of the present invention. The
clip 50 had the same overall dimensions as the C-shaped retainer
clip, i.e. top leg 0.875'', bottom leg 1.5'', and height 3.25''.
The diagonal leg was 3.57'' long. The Z-shaped retainer clip 50 and
its placement within a wall support 14 above a ceiling panel 12 are
shown schematically in FIGS. 5a, 5b, and 5c.
[0044] The governing performance failure mode was buckling of the
diagonal leg and the load required was 873 pounds.
[0045] From the foregoing description, one skilled in the art can
easily ascertain the essential characteristics of the invention
and, without departing from the spirit and scope thereof, make
various changes and modifications to adapt it to various
usages.
* * * * *