Note: Descriptions are shown in the official language in which they were submitted.
SCREW SLOT RUNNEP~ SYSTEM
BACKGROUND OF T~E INVENTION
This invention relates generally to grid systems for
suspension ceilings or the like, and more particularly to a
novel and improved screw slot grid system for suspension
ceilings .
Prior Art
Screw slot grid systems for suspension ceilings are
known. Such systems are often used where it is necessary to
mount an accessory for support by the ceiling grid system.
For example, in hospitals it is often necessary to ~ount a
curtain track on the ceiling so that a privacy çurtain can be
drawn around a patient's bed. When the ceiling is formed
with a screw slot ~rid, it is a simple matter to mount the
track along substantially any portion of the ce;ling by
inserting a T-bolt fastener in the screw slot at intersec-
tions between the track and the grid and then mount -the track
on the T-b~lt.
Because the T-bolt can be positioned substantially
anywhere on the grid, it is possible to mount the track in
substantially any desired location. An example of one type
of prior art screw slot grid or runner system is described in
U~S. Patent No. 4,021,986.
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In accorclance wi-th one important aspec-t of the
inver!-tion, a novel and improved joint s-truc-ture is provided
for scre~ slot runner systems. Such joint s-truc-ture is
arranged to provide an improved ceiling ~ppearance in which
the exposed portions of the grid appear to provide a mitered
joint to eliminate -the but-t joint appearance of the prior
ar-t.
~ ccording to the presen-t invention -there is provided
a suspension ceiling grid system including elon~ated
runners formed with a bulb at their upper edge, a planar
central we~, and an open channel at their lower edge. The
open channel is defined by lateral flanges extending in
opposite directions from the lower edge of the weh, a
pair of laterally spaced, substantially parallel channel
sidewalls, and inturned lips extending laterally toward each
other from the sidewalls and terminating a-t spaced and
opposed inner edges, the lips cooperating to define a
lon~itudinal opening along the lower side of the channel.
The ~rid system includes first runners havin~ end connec-tors
adapted to connect with second runners at predetermined
locations. The second runners provide notches in their
channels at the ]ocations, the notches extending through
the sidewalls and a portion of the associa-ted flange leaving
intact a portion of the flanges~ex-tending past the notch.
the lips at the ends of the first runners and adjacent to
the notches of the second runners are shaped to fit together
to form a miter joint when the runners are interconnected.
The sidewalls and flanges of the ends of the first runners
fit into the notches and cooperate to provide a stable joint
and -to provide an appearance of a full miter join-t.
In a specific embodiment, a system is provided in
which the grid includes typical "main runs" and cross runs,
where cross runs are connected between parallel main runs.
In such embodiment, the main runs are provided by a plurality
of main run modules connected by separate connector clips.
In such embodiment, the main runs are assembled from whatev~r
number of modules are required to produce the required main
run length~ The ends of each main run module are shaped to
provide one-half of a mitered joint and, when assembled with
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a connector clip, provide a full joint adapted to receive a
cross run end. The opening through which the cross run end
connector extends is provided in the connector clip itself so
the associated cross run connector actually connects to the
main run connector clip. The main run connec~or clip is
structured to provide a strong end connection between aligned
end-ccnnected main run modules.
The cross section of the grid runners provides a
closed bulb at the upper extremity, a central web, and an
open channel at the lower extremity adapted to receive the
head of a T-bolt. In the illustrated embodiment, a separate
U-shaped reinforcing element is enclosed within the bu].b ~o
provide additional strength in the bulb.
These and other aspects of this invention are illus-
trated in the drawings, and are more fully described in the
following specification.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of an assembled connec-
tion in a T~slo~ runner system in accordance with this inven-
tion;
FIG. 2 is an exploded view similar to FIG. 1, illus-
trating the end connectors aligned with but spaced from the
through member;
FIG. 3 is an enlarged cross section of the runners;
FIG~ 4 is a side elevation of the end o a runner
used in either the basketweave system or as a cross runner in
æa main run cross run-type system;
FIG. 5 is a bottom view, taken along line 5-5 of
FIG~ 4,
FIG. 6 is a side elevation o a through runner
illustrating the structure adapted to receive the end connec-
tion of FIGS. 4 and 5;
FIG. 7 is a bottom view taken along line 7-7 of FIG~
6:
FIG. 8 is a side elevation of the end connection of
a main run system in which a connector clip is used to con-
nect a paîr of aligned main run modules;
FIG. 9 is a cro.ss section taken along line 9-9 of
FIG. 8; and
FIG. 10 is a cross section taken along line 10-10 of
FIG. 8, illustrating the connection between the main run
modules and the main run connector clip.
DETAILED DESCRIPTION OF T~E D~WINGS
A suspension ceiling grid system in accordance with
the present invention consists of an assembly of a plurality
of runners interconnected to form rectangular or square open-
ings proportioned to receive ceiling panels or, in some in-
stances, lighting fixtures or the like~ Such panels are sup-
ported at their edges within the openings by the grid systemO
As best illustrated in ~IGS. 1 through 3~ the illus-
trated grid system is formed of runners 10 having a closed
bulb 11 which is generally rectangular in shape, a central
web 12, and an open channel 13 at ~heir lower ex~remity. The
runners are symmetrical about a central plane along which the
central web 12 extends.
Referring to FIG. 3, the runner is for~ned of a
shaped piece of sheet material, preferably sheet metal, pro-
viding a central portion 14 extending to spaced and parallel,
depending walls 16 and 17 which form the sides of the bulb
llo At the lower extremities of the depending walls 16, the
metal is bent inwardly to provide converging~ inclined wall
portions 18 and 19, which cooperate to form the lower portion
of the bulbo
Extending downwardly in face~to-face adjacency are a
pair of web portions 21 and 22 which cooperate to form a
double thickness web 12 extending from the bulb 11 to the
channel 13. At the lower extremity of the web portions 21
and 22, the material is bent in opposite directions to form
flange portions 23 and 24 whi~h cooperate to form the upper
side of the channel 13. Depending channel wall portions 26
and 27 respectively extend from the extremities of the flange
portions 23 and 24 in spaced and parallel relationship, and
cooperate to define the sidewalls of the channel 13. At the
lower extremity of each of the channel wall portions 26 and
27, the material is inturned to provide converging l;ps 28
and 29. At the inner ends of each lip the material is bent
back upon itsel at 31 and 32 to provide additional stiffness
and a finished edge 40. The edges 40 of the lips are spaced
apart a small distance so that a T-bolt or the like can be
inserted into the channel and after being rotated 90 degrees,
is supported on the lips within the channel so that the shank
of the bolt extends down from the runner. Such T~bolts (not
illustrated) can be positioned at any desired location along
the channel 13 and provide a simple qtructure for supporting
substantially any desired items, such as a curtain track or
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the like~ from the gr;d system. Similarly, lighting ixtures
or other types of accessories can be supported from the grid
system in this convenient manner~ -
In order to provide additional strength and rigidityin the bulb 11 of the runners, it is preferable to enclose
within the bulb a U-shaped reinforcing element 32 which
extends along the central portion 14 and down along each of
the depending walls 16 and 17. Such reinforcing member ls
preferably lance-stitched at 33 to the depending wal~s. Such
reinforcing member is not illustrated in FI&S. 1 and 2 foY
purpo.ses o~ simplification. Reference should be ~lade to U.S~
Patent No. 4,206,578, assigned to the assignee OL the present
inventionr for a more detailed description of the manner in
which such reinforcing elements are incorporated into the
bulbs of suspension ceiling runners.
Mounted on the ends of the CrO5S runners usea in
main xun~cross run grid systems and on the ends of the run-
ners used in a basketweave grid system are end connectors 34,
which project through an open;~g 36 formed in the web 12 of
the through runner~ as best illustrated in FIGS. 2 and 3.
The struct~re of such end connectors and the manner of inter-
connecting when inserted from opposite sides through the
opening 36 are fully described in U.S. Patent No~ 4,108,563.
At each location where a perpendicular runner ;s ~o
be connected, the throuyh runners are provided with a notch
(best illuxtrated in FIG. 2) which receives the mating end of
the connecting runner. A similar notch is ~ormed in each
side of the runner which respectively cut through the channel
wall portions 26 and 27 to provide side edges 3a which are
space~ apart a.distance necessary to receive the channel
sidewalls 26 and 27 of the connect;ng runner with a small
clearance. In aadition, the flange portions 23 and 24 are
cut back at the notch through a distance of approximately
one-half their lateral width to a longitudinal edge 39. By
forming the notch 37 so that it extends only a portion of the
way along the flange portions 23 and 24, a structure is pro-
vided in which a substantial part of the flange portions
remains intact to provide runner strength past the connecting
notch.
At the notch, the ends of the converging lips 28 and
29 are cut at a 45-degree angle to provide mitered ends 41
which mate with mitered ends 42 of the connecting runner ~o
as to provide an attractive miter-type joint between the
intersecting lips of connecting runners, as best illustra~ed
in FIG. 1. This structure, therefore, eliminates the butt-
type connector appearance of the prior art as exemplified by
U.S. patent No. 4,021,986, supra.
In addition, the illustrated embodiment locates the
edge 33 in vertical alignment with the inner edges 40 of the
converging lips 28 and 29 of the through runner so that the
joint provided by the abutting ends 43 and the edges 39 is in
vertical alignment with the inner edges 40 of the converging
lips in an assembled grid and tends to be obscured from view
when the grid system is viewed from the room in which it is
i.nstalled. Consequently, the visual impression provided in
an installed grid system is that a full miter joint is pro-
vided at each intersecting connection even though part of the
flange portion remains to extend past the connection and pro
vide additional strength. Further, the channel wall portions
26 and 27 of the connecting members extend past the edges 38
of the through member with a close fit to provide a strong~
fully stabil;zed interconnection between the runners which
resists any tendency for the connecting runners to twist with
respect to the through runner~,
As best illustrated in FIG. 4, the ends of the chan-
nel wall portions 26 and 27 are inclined forwardly from the
end of the m.iter joint 42 and the end 43. This ensures that
the channel sidewall portion of a connecting runner extends
into the notch formed between the edges 38 oE the through
runner~
A second embodiment is illustrated in FIGS. 8
through 10 in which a connector clip is provided to assemble
runner modules in an end-to-end relationship to provide main
runs of substantially any length~
The main run modules 51 are provided with the same
cross section as in the irst embodiment, and therefore pro-
vide a bulb 11~ a web 12, and an open channel 13. The ends
of the modules 51, however, are provided with a shape allow-
ing the modules to be connected together by a connector clip
52 having a first or web mating portion 53 which, in an
assembly, exten~s along one side of the web 12 from the chan-
nel at its lower edge to the bulb 11 at its upper edge. The
clip also provides a lateral portion 54 extending to a bulb
engaging portion 56, which engages one side of the bulb 11
and extends to a lateral portion 57 which engages the upper
wall of the bulb 11.
A snap-in locking system, best illustrated in FIG.
10, is provided to interconnect the runner modules 51 and the
clip 52. Such locking system includes two tabs 58 and 59
which cooperate to lock with each of the runner moZules 51 by
extending through an opening 61 in the web 12 in the case of
the tabs 58 and extending over the end edge o~ the web 12 in
the case of the tabs 59. The clip is assembled with the
respective runners by merely aligning the two and then moving
the clip and runner axially with respect to each other until
the assembled position of FIG. 10 is reached. In such posi-
tion, a projection 62 on the clip associated with each of the
runner modules 51 snaps into the opening 61 in the web 12 to
engage the edge thereof opposite the tab 58. This provides a
locking connection which prevents the clip from being removed
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from the end of the associated runner and, in effect, is a
permanent connection which is easily created by slipping the
parts together.
The ends of the runner modules are formed with one-
half of a notch structure 37 so that when the adjacent ends
of the two runner modules are ~onnec~ed by the connector 52,
they cooperate ~o provide a connector notch 37 having the
same structure described above in connection with the flrst
embodiment. Therefore, the structural detail is not again
set forth, and the previous description applies to this
embod iment.
In addition, the ends of the webs of the runner
modules are cut back, as indicated by the dotted line 66, so
that the connector clip 52 is exposed on both s-des of the
assembly. Located in the connector clip is an opening 36'
having the same shape as the opening 36 of the first embodi-
ment, and which is adapted to receive end connectors 34 dis-
cussed above. The material of the clip around the opening 36
is deformed laterally, as indicated by the dotted line 50 in
FIG. 8, so that the opening is displaced from the plane of
the clip back to the plane of the web 12, as indicated in
FIG. 10. Therefore, the end connectors of the cross runners
are properly centered and the joint fits properly
Once the assembly is formed by connecting adjacent
runner modules with a connector 52, cross runners having the
same end configuratlon discussed above are attached at the
intersections by inserting the connectors 34 from opposite
sides through the opening 36~. Preferably~ the ends oE the
runners are shaped so that they do not overlap the openin~s
67 formed in the mounting clip through which support wires
may be inserted to suspend the runner assembly.
The connector clip 52 is preferably formed of a
material somewhat thicker than the material used to form the
runners, so that a strong bridging connection is provided
between the adjacent runner modules. Further, because the
connector clip extends along the web and up around one side
of the bulb, a strong connection is provided in which the
connection is substantially as strong as the runner modules
along their lengths. With this embodiment, main runs of
substantially any length can be assembled from an appropriate
number of runner modules. Further~ since the suppor~ wires
can be put in place on the connector before the connector is
assembled with a given runner module, a given runner can be
assembled in its installed position.
Although the preferred embodiments of this invention
have been shown and described, it should be understood that
various modifications and rearrangements of parts may be
resorted to without departing from the scope of ~he invention
as disclosed and claimed herein.
