U.S. patent number 3,708,932 [Application Number 05/043,130] was granted by the patent office on 1973-01-09 for ceiling system.
This patent grant is currently assigned to Conder International Limited. Invention is credited to Malcolm Bailey, John Colin Downer.
United States Patent |
3,708,932 |
Bailey , et al. |
January 9, 1973 |
CEILING SYSTEM
Abstract
In order to prevent buckling or excessive displacement or
deflection of ceiling support members in a fire, a gap is left
between ceiling support members but the ceiling support members are
secured together and positively spaced apart by a spacing and
supporting arrangement which includes fusible material so that in a
fire, the fusible material will melt and allow the width of the gap
to alter while at least one of the support members remains
supported on the other. This prevents collapse of the ceiling and
improves the fire resistance of the building.
Inventors: |
Bailey; Malcolm (Alresford,
EN), Downer; John Colin (Chandler's Ford,
EN) |
Assignee: |
Conder International Limited
(Winchester, Hampshire, EN)
|
Family
ID: |
10272012 |
Appl.
No.: |
05/043,130 |
Filed: |
June 3, 1970 |
Foreign Application Priority Data
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|
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Jun 4, 1969 [GB] |
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28,207/69 |
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Current U.S.
Class: |
52/232;
52/506.08; 52/781 |
Current CPC
Class: |
E04B
9/22 (20130101); E04B 9/008 (20130101); E04B
9/064 (20130101); E04B 2009/062 (20130101) |
Current International
Class: |
E04B
9/06 (20060101); E04B 9/00 (20060101); E04B
9/22 (20060101); E04c 002/00 () |
Field of
Search: |
;52/484,488,489,495,665,669,DIG.5,232 ;287/189.36A ;85/5
;24/73P |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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|
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|
|
|
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1,021,555 |
|
Dec 1957 |
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DT |
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1,005,866 |
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Sep 1965 |
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GB |
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109,227 |
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Jul 1964 |
|
NL |
|
Primary Examiner: Sutherland; Henry C.
Claims
We claim:
1. A ceiling support system comprising: a set of substantially
parallel main ceiling support members of inverted channel section
configuration, a set of subsidiary ceiling support members
interconnecting said main members, primary ceiling support means
for holding said main and subsidiary members in a horizontal plane,
supporting guide means for guiding relative movement between the
respective main and subsidiary members in said horizontal plane,
said supporting guide means including means for slidably supporting
the subsidiary members on the main members, and spacing means
operatively connected to a respective main member and a respective
subsidiary members for normally spacing said main and subsidiary
members a predetermined distance from one another to form a gap
between the end of the subsidiary member and the side of the main
member, said spacing means being located in position on the main
member by way of aperture means in the upwardly facing side of the
main member and being interconnected with said subsidiary member by
interengagement with top portions of said subsidiary member such
that said spacing means can be attached from the top to respective
subsidiary and main members after they are held in place in their
final assembled positions by the primary ceiling support members,
said spacing means being constructed of a relatively more fusible
material than said support members and said supporting guide means
such that melting of the fusible structure of the spacing means in
the event of a fire will permit the ends of subsidiary members to
move in a horizontal plane in the direction of the main members to
thereby reduce the risks of buckling and collapse of the ceiling
system.
2. A system according to claim 1, characterized in that the spacing
means includes a bridge shaped member for each respective junction
of main and subsidiary members, each of said bridge shaped members
spanning a respective main member and holding at least one
subsidiary member in position with respect to said main member.
3. A system according to claim 2, characterized in that gaps are
formed between ends of the subsidiary members and edges of said
main members at the respective junctions and between the ends of
respective aligned main members at positions spaced from the
respective junctions, said spacing means and said supporting means
further including means for permitting relative movement of the
aligned main members in a single axial direction while preventing
substantial relative movement of the main members in directions
other than said axial direction.
4. A system according to claim 2, characterized in that said bridge
shaped member includes a part for engaging in a detent provided on
an end portion of said at least one subsidiary member.
5. A system according to claim 4, characterized in that said bridge
shaped member includes uprights of hollow section which are open in
the downward direction, the part for engaging the detent being a
wall of said hollow section disposed away from said main
member.
6. A system according to claim 1, characterized in that means are
provided for snap-fitting said spacing means into position on said
ceiling support members, and in that at least one resilient
ratchet-type projection is provided on said spacing means for
engagement with the aperture means of said main ceiling support
member.
7. A ceiling support system comprising a plurality of ceiling
support members arranged for supporting ceiling panels, spacing
means operatively connected to at least two adjacent support
members for spacing said at least two adjacent support members a
predetermined distance from one another to form a gap therebetween,
and supporting guide means for guiding relative movement between
the at least two adjacent support members in a horizontal plane,
said spacing means including structure constructed of a relatively
more fusible material than said support members and said supporting
guide means, whereby the fusible structure of the spacing means
will melt in the event of a fire permitting the adjacent support
members to move in a horizontal plane relatively to one another
thereby reducing the risks of buckling and collapse of the ceiling
system, wherein at least one of said gaps is located between
adjacent ends of adjacent aligned ceiling support members, wherein
said spacing means and said supporting guide means include means
for permitting relative movement of the aligned ceiling support
members in a single axial direction while preventing substantial
relative movement in directions other than said axial direction,
and wherein said spacing means includes a longitudinal spacing
members spanning said gap and a fusible securing member for
securing the spacing member to at least one of said ceiling support
members, said spacing member operatively engaging both of said
adjacent ceiling support members to normally hold said ceiling
support members in a fixed position with respect to one
another.
8. A system according to claim 7, characterized in that said
spacing member and one of said ceiling support members have
registering apertures, and in that said fusible securing members
includes a peg-like member inserted through said registering
apertures.
9. A system according to claim 7, characterized in that said
spacing member and said ceiling support member have registering
apertures, said fusible securing member being bridge shaped for
spanning the respective ceiling support member and including at
least one resilient ratchet-type projection engaging in said
registering apertures.
10. A ceiling support system comprising a plurality of ceiling
support members arranged for supporting ceiling panels, spacing
means operatively connected to at least two adjacent support
members for spacing said at least two adjacent support members a
predetermined distance from one another to form a gap therebetween,
and supporting guide means for guiding relative movement between
the at least two adjacent support members in a horizontal plane,
said spacing means including structure constructed of a relatively
more fusible material than said support members and said supporting
guide means, whereby the fusible structure of the spacing means
will melt in the event of a fire permitting the adjacent support
members to move in a horizontal plane relatively to one another
thereby reducing the risks of buckling and collapse of the ceiling
system, wherein at least one of said gaps is located between
adjacent ends of adjacent aligned ceiling support members, wherein
said spacing means and said supporting guide means include means
for permitting relative movement of the aligned ceiling support
members in a single axial direction while preventing substantial
relative movement in directions other than said axial direction,
and wherein said adjacent aligned ceiling support members are
constructed as channel sections having internal support surfaces
within and on each side thereof, said internal support surfaces
having recesses thereunder, said supporting means including a
sleeve member mounted on the outside of the channel sections and
having inwardly projecting bottom lips engaging in said
recesses.
11. A ceiling support system comprising at least one main ceiling
support member extending longitudinally along a first axis, two
subsidiary ceiling support members arranged at opposite sides of
said main member and extending longitudinally along a second axis
arranged at an angle with respect to the first axis, and a
connecting means operatively connecting said main member to both of
said subsidiary members at a position spaced from the ends of the
main member, said connecting means including a connecting member
having a downwardly open U-shaped configuration straddling the main
member such that a connecting leg is disposed on each of two
opposite sides of said main member, that portion of the U-shaped
connecting member between the connecting legs being fastened to
said main member by fastener means engaged in an aperture on said
main member, each of said connecting legs being connected to an end
of a respective subsidiary member by way of detent means positioned
on said subsidiary member and said connecting leg such that the
respective ends of the subsidiary members are held in a
predetermined distance from vertically extending outer surfaces on
said main member, whereby the subsidiary member can move along the
second axis said predetermined distance upon disengagement of the
connecting means prior to abuttingly engaging said main member.
12. A system according to claim 11, characterized in that said main
member is constructed as a three sided box-shaped channel member
with the open side facing downwardly, said channel member including
outwardly extending lip portions for slidably supporting bottom end
portions of said subsidiary members, and in that said first and
second axes are substantially perpendicular to one another and are
in a common horizontal plane.
13. A system according to claim 12, characterized in that said
connecting member is constructed of material that is more fusible
than the material of the ceiling support members, whereby during a
fire the connecting member becomes inoperable and the subsidiary
members are permitted to slide freely on the lip portions in the
direction of the vertically extending outer surfaces of the main
member.
14. A system according to claim 13, characterized in that said
detent means include a cut-out recess portion in the respective
subsidiary members and an outer wall portion of the respective
connector legs.
15. A system according to claim 14, characterized in that said
fastener means includes a peg-like member having two resilient
ratchet type projections for engaging in an aperture at the top of
the main member.
16. A fusible securing device for securing a first ceiling support
building member of a three sided rectangular box-shaped
configuration with the open side facing downwardly to two further
ceiling support building members extending perpendicularly to and
at opposite sides of said first member in such a manner as to
permit the building members to move with respect to one another
upon melting of the fusible device in a fire; said securing device
being of a downwardly open U-shaped configuration for straddling
said first member with securing legs of said device disposed at
each of two opposite sides of said first member, said device
further including at least one resilient ratchet-type projection
extending downwardly from that portion of the device
interconnecting the securing legs for snap-fitting engaging in a
corresponding aperture at the top side of the first member, and
each of said securing legs having detent parts for engaging with
respective detents at the top portions of said further members for
holding the further members a predetermined distance from
vertically extending outer surfaces at the sides of the first
member whereby said device can be inserted from above onto said
building members and whereby said further members can move said
predetermined distance upon melting of said securing device prior
to abutting engagement with said first member.
17. A securing device according to claim 16, wherein said securing
legs each include uprights of hollow section and open at the
bottom, and wherein said detent part is an outer wall of said
hollow section which is engageable in a detent on the end portion
of the respective further member.
Description
This invention relates to a ceiling system for a building and
particularly, but not exclusively, to a suspended ceiling system,
and can be applied to the system described in British Patent
Specification No. 1,154,081 the description of which is
incorporated herein by reference. Normally, ceiling systems, and
suspended ceiling systems in particular, provide a ceiling which
has either insulation qualities, decorative qualities, sound
absorption qualities, fire protective qualities, or a combination
of these properties, and is suspended from the floor above, or
roof, using straps or hangers. The ceiling is usually supported on
either T-section, bulb T-section, or I-section bearers, and uses
either an exposed or secret method of fixing. The ceiling can be
supported at a large number of points, and it is an object of the
invention to arrange the ceiling so that both under normal
conditions and in a fire, displacement or deflection of the ceiling
support members can be within acceptable limits. In a fire, the
ceiling should remain as flat and as dimensionally stable as
possible in order that gaps should not occur, nor ceiling panels
fall out.
According to the invention, a gap is left between the end of one
ceiling support member and the adjacent part of another ceiling
support member, the ceiling support members being secured together
and positively spaced apart by a spacing and supporting arrangement
which includes fusible material so that in a fire, the fusible
material will melt and allow the width of said gap to alter whilst
at least the first-mentioned ceiling support member remains
supported on the other ceiling support member; the ceiling support
members may remain mutually supported on each other.
According to the invention, a gap may be left between the adjacent
ends of adjacent, aligned ceiling support members with the ceiling
support members secured together and positively spaced apart by a
spacing arrangement which includes fusible material so that in a
fire, the fusible material will melt and allow the sections to move
axially with respect to each other whilst remaining secured
together as regards substantial relative movement in other
directions. The spacing arrangement may include a longitudinal
spacing member which spans said gap, the spacing member being
secured to each ceiling support member as regards longitudinal
movement, a fusible securing member (e.g. a peg-like member
inserted through registering apertures in the spacing member and in
the ceiling support member) being used to secure the spacing member
to at least one of the channel sections. The spacing member can lie
along the top of the ceiling support member, e.g. being a strip. In
this case, the securing peg-like member may be a projection on the
bridge-shaped securing device referred to hereafter.
The support members can be connected by sleeve members on the
outside of the channel sections, the sleeve members having
inwardly-projecting bottom lips which engage in the recesses
provided under internal support surfaces of channel section support
members. The sleeve members are a sliding fit within or over the
channel sections until secured so that in a fire the tendency of
the channel sections to buckle is reduced or prevented.
According to this invention, a ceiling system may have two parallel
sets of members, a first set of generally parallel main members and
a second set of subsidiary members interconnecting (and preferably
generally at right angles to) the first set of members, the sets of
members being secured together by securing devices formed of or
including fusible material so that in a fire, the fusible material
will melt and allow the sets of members to move with respect to
each other, the sets of members and securing devices being arranged
such that the subsidiary members are slidably supported by the main
members when the fusible material melts. One simple way of
achieving this is to have the end portions of the subsidiary
members resting on external support surfaces provided by
projections on the main members. If the members are channel
sections, they may have sidewalls having their lower portions
curved inwards through approximately 90.degree. and then downwards
and outwards through approximately 180.degree. to continue as
outwardly-projecting lips.
The securing device may be just a clamp for clamping the relevant
members together. One useful clamp-type securing device is a
bridge-shaped (i.e. generally inverted U-shaped) member which spans
the main member and holds the subsidiary member down. The
bridge-shaped securing device may have a part for engaging in a
detent on the end portion of the subsidiary member, conveniently on
the top of the subsidiary member. The detent may be a transverse
slot in the subsidiary member, for instance cut with a saw. The
upright of the bridge may be of hollow section and open at the
bottom so that the outer wall (the wall remote from the main
member) can act as said part and enter the detent. The securing
device is preferably snap-fitted into position. One possible
snap-fitting is to have at least one resilient, ratchet-type
projection on the securing device which engages in an aperture in
the main member. If the main member is an inverted channel section
and the securing device is bridge-shaped, the projection(s) may
engage in an aperture in the top of the section.
The fusible material may be plastic, and in general, the fusible
material preferably melts below 200.degree. C.
The invention will be further described, by way of example, with
reference to the accompanying drawing, of which:
FIG. 1 is a perspective view, partly in section and partly broken
away, of a ceiling system in accordance with the invention;
FIG. 2 is a cross-section through a channel section in accordance
with the invention, showing a closure panel, a bridge member and a
pipe conduit;
FIG. 3 is a cross-section through a connection between two aligned
channel sections;
FIG. 4 is a side view of two channel sections connected
together;
FIG. 5 is a cross-section through a channel section showing how the
interconnecting members are secured;
FIG. 6 is a similar cross-section to FIG. 5, showing a slightly
different arrangement;
FIG. 7 is a top view of a spacing bar shown in FIGS. 3 to 6;
and
FIGS. 8 to 11 illustrate four different ways of fixing the ceiling
panels in position, each Figure showing two partial sections along
two vertical planes at right angles to each other, one partial
section being taken through the channel section and the other
partial section being taken through a T-bar.
The suspended ceiling system of FIG. 1 has metal, cold-rolled
channel sections 1, which form a grid with subsidiary T-bars 2,
extending at right angles to the sections 1. The ends of the T-bars
2 are notched or rebated at 3 (see FIGS. 6) and have cut-outs 4
(FIG. 5) so that the ends of the T-bars can either rest on lips 5
of the channel section 1 (FIG. 5) or can have the notches 4 resting
on the slips 5 (FIG. 6). The arrangement of FIG. 5 is shown in FIG.
1. Protruberances (opposite the dimples 24) are formed on the lips
5 for locating the ends of the T-bars 2.
The building has a main beam 25 which supports a concrete floor
unit 26. Either (a) chevron-slotted angle strips 27 are attached to
the floor units 26 by means of hook bolts 28, and the channel
sections 1 are suspended from the angle strips 27 by means of
suspension rods 29 (as shown) or (b) the channel sections 1 are
suspended direct from the floor units 26 (not shown). Apertures or
deliniated apertures (scored or pressed rings in the surface of the
metal which can easily be knocked out) are provided in the top of
the channel sections 1 and are used to attach the suspension rods
29 direct to the channel sections 1.
As can be seen more clearly in FIGS. 4-6, the T-bars 2 are secured
in position by bridge-shaped T-bar connectors 6 which are formed of
a fusible material such as self-extinguishing nylon (nylon
including a flame-retardant). The connector 6 spans the channel
section 1 and two ratchet-type projections 7 (forming a peg-like
member) have been inserted through a circular hole in the top of
the channel section 1 and hold the connector 6 securely in
position. As can be seen in FIGS. 5 and 6, the upright 8 of the
connector 6 is of hollow section and its outer wall 9 engages in a
cut-out 10 in the top of the end portion of the T-bar 2, securing
the T-bar 2 against movement away from the channel section 1.
The cross-section of the channel section 1 can be seen in FIG. 2.
The top has each edge portion curving downwards through
approximately 90.degree. to continue as a respective sidewall. The
lower portion of the sidewall curves inwards through approximately
90.degree. and then downwards and outwards through approximately
180.degree. to continue as the outwardly-projecting lip 5. The
inwardly-directed portions of the sidewalls provide internal
support surfaces 12. As shown in FIG. 2, the internal support
surfaces 12 may be used to support closure panel in the form of a
snap-fitted plastic strip 13 (e.g. formed of stiff, polyvinyl
chloride) for closing the channel section 1. Bridge members 14 may
be provided at intervals along the channel section 1 for supporting
services such as electrical wiring.
The section 1 shown in FIG. 2 is cold-rolled from a 200 mm wide
steel strip.
The lengths of channel section 1 are joined together by sleeves 15
whose lower lips engage under the support surfaces 12. The sleeve
15 is clamped by a bolt 16 running across in a gap between the ends
of the channel sections 1, the clamp being not so tight as to
prevent longitudinal sliding movement of the channel sections 1 if
a fire occurs. A spacing member in the form of a spacer bar 17 (see
FIG. 7) lies along the top of the channel section 1. The spacer bar
17 locates the channel sections longitudinally; the projections 7
on the connectors 6 on either side of the connection pass down
through respective registering holes in the end portions of the
spacer bar and in the tops of the channel sections 1. Earth
continuity is provided by spacer bar and by the sides and bottom
lips of the sleeve 15.
Ceiling panels 18 are supported by the lips 5 of the channel
sections 1 and by the bottom flanges of the T-bars 2. A choice of
five different arrangements for the ceiling panel is provided, as
follows:
i. The channel section lips 5 and the T-bar flanges are exposed
(see FIG. 8).
ii. A full secret fix is provided, the panels 18 passing under the
channel sections 1 but the flanges of the T-bars 2 engaging in side
grooves in the ceiling panels 18, the T-bars 2 being lower than the
channel sections as in FIG. 6 (see FIG. 9).
iii. A semi-secret fix is provided, the channel section lips 5
being exposed but the flanges of the T-bars 2 engaging in side
grooves in the ceiling panels 18, the T-bars 2 being higher in
relation to the channel section 1 than is shown in FIG. 5 (see FIG.
10).
iv. A recessed semi-secret fix is provided, the lower edges of the
ceiling panels being rebated where they rest on the channel section
lips 5 (see FIG. 11 and FIG. 2).
v. The ceiling panels 18 are not rebated but have sliding bolt-like
catches on their upper surfaces for hooking over the channel
section lips 5 and the flanges on the T-bars 2, the ceiling panels
18 providing a continuous ceiling beneath the channel sections 1
and the T-bars 2 (see FIG. 3).
In any of these arrangements, abutting edges of ceiling panels can
be grooved and metal strips in the form of splines or even small
T-bars can be inserted in the grooves to align the ceiling panels
properly; if small T-bars are used, their end portions can be
slightly joggled (displaced upwards) and rest on the flanges of the
T-bars 2. The ceiling panels can be tiles of any suitable type, for
instance mineral fiber board or asbestos board.
A light fitting clip 20 is shown in FIG. 1, clipped to the lips 5
of the channel section 1.
Pipe conduits 22 (see FIG. 2) extend between adjacent channel
sections 1 and provide earth continuity and a conduit for services.
An inspection Tee 23 is used for connection and a male bush 24 is
screwed up through an aperture in the top of the channel section 1
and into the Tee.
FIG. 1 shows a partition 30, and FIG. 5 shows the mounting in more
detail. A retaining bar 31 rests on the internal support surfaces
12, and carries a threaded spindle 32. A retaining channel 33 is
clamped up against the lips 5 by a nut 34. The top of the partition
is inserted up in the retaining channel 33.
It can be seen that the ceiling provides for sliding movement
should a fire occur. Steel expands by about 40 mm for a 3.6 meter
length and a temperature rise of 1000.degree.C.
* * * * *