|Publication number||US3722933 A|
|Publication date||Mar 27, 1973|
|Filing date||May 7, 1971|
|Priority date||May 7, 1971|
|Publication number||US 3722933 A, US 3722933A, US-A-3722933, US3722933 A, US3722933A|
|Original Assignee||Armstrong Cork Co|
|Export Citation||BiBTeX, EndNote, RefMan|
|Patent Citations (3), Referenced by (10), Classifications (11)|
|External Links: USPTO, USPTO Assignment, Espacenet|
United States Patent 1 Nute, Jr.
1 51 Mar. 27, 1973 |5 EXPANSION JOINT FOR A FIRE- RATED CEILING SYSTEM  Inventor: Ernest B. Nute, Jr., Mountville, Pa.
 Assignee: Armstrong Cork Company, Lancaster, Pa.
22 Filed: May 7,1971
 Appl. No.: 141,243
 US. Cl ..287/189.36 A, 52/232, 52/664  Int. Cl ..Fl6b 7/04 Field ofSearch ..287/189.36 A,
 2 References Cited UNITED STATES PATENTS 2,990,921 Wilde ..28-7/189 36 A Manske ..287/20.92 W Meredith ..287/l89.36 A X Primary ExaminerDavid J. Williamowsky Assistant ExaminerWayne L. Shedd Attorney-Clifford B. Price  ABSTRACT The cross member of a ceiling system is connected to the main runner of a ceiling system by a slide lock tab. A tab is bent at a 90 angle to the longitudinal axis of the cross runner. This tab slides into a fastener on the main runner structure. The connecting element between the cross member proper and the tab is corrugated so that, during a tire condition, the cross member can expand without buckling. Expansion occurs due to the collapse of the corrugated structure.
5 Claims, 2 Drawing Figures Patented March 27, 1973 INVENTOR ERNEST B. UTE,JR. BY 6 r ATTORNEY EXPANSION JOINT FOR A FIRE-RATED CEILING SYSTEM BACKGROUND OF THE INVENTION 1. Field of the Invention The invention is directed to a ceiling suspension system and, more particularly, to a joint structure to render the ceiling system capable of resisting buckling during fire.
2. Description of the Prior Art A number of patents have issued on fire-retardant ceiling suspension systems. Normally, the thin metal, long extending parts of a ceiling suspension system will expand greatly when there is a fire in the area below the suspended ceiling. If a means is not provided-to permit these long members to expand, they will buckle and drop the ceiling boards to the floor. This then exposes the area above the ceiling to destruction from the fire. Consequently, it is advantageous for the suspension system to expand and not buckle and thereby hold the ceiling panels in position and thus retard the spreading of fire.
U. S. Pat. No. 3,159,252 is typical of an expansion system for a ceiling suspension system. In FIG. 6 of that patent, there is shown a buckling that occurs in the suspension system during fire. This buckling is so controlled that the ceiling boards are still held in place by the suspension system. Many other patents exist in the art, and they provide a number of different ways for allowing expansion of the runners ofa ceiling system.
The idea of using a tab to fasten a cross member to a main runner member of a ceiling system is old in the art. Normally, this tab would be placed on the end of the straight rib section of the vertical web of the cross member. Consequently, any expansion of the cross member would result in a spreading action being applied to two adjacent main runners. This would-then permit the ceiling board to drop out of position from between the main runners.
SUMMARY OF THE INVENTION The main runner of a ceiling suspension system is provided with a fastening means to receive the tab on the end of a cross member. The tab on the cross member extends at 90 angle from the longitudinal dimension of the cross member. This tab slides into the fastening member on the main runner, and this holds the cross member relative to the main runner member. The connecting element between the tab and the main body of the cross member is provided with a corrugated configuration. Also, the horizontal flange member of the cross member is provided with a small lip. Consequently, when heat causes expansion of a cross member, the cross member is able to expand by action of the collapsing of the corrugated structure and a riding up of the horizontal flange of the cross member up over the horizontal flange of the main runner. Consequently, expansion of the cross member is permitted without buckling or bending of the cross member in the direction of its longitudinally extending axis.
BRIEF DESCRIPTION OF THE DRAWING FIG. I is a top view of the joint structure herein; and FIG. II is an isometric view of the joint structure of FIG. I.
DESCRIPTION OF THE PREFERRED EMBODIMENT A conventional ceiling system is composed of a plurality of long main runner members which usually extend parallel to each other about 4' apart. The main runners are generally 12 feet long and are interconnected together to form a span which runs from one side ofa room to the opposite side. Spanningthe 4 foot gap between the main runners, every 2 feet there are placed short cross members. In the grid pattern of 2 X 4 feet, there are positioned ceiling boards. The main runners areprovided with a plurality of different fire-expansion systems. The invention herein is directed to a joint for connecting the cross member to the main runner to provide the cross member with the capability of expanding during tire.
The main runner assembly 2 like most main runner assemblies is composed of a horizontal flange 4 and a vertical web 6. On the vertical web 6 of the main runner, there is positioned a fastening means 8 for holding the cross member in position relative to the main runner. The fastening means is basically two little taBs 10 which are bent to face each other and define a slide structure into which can be inserted a portion of the cross member. The cross member 1 1 also has a vertical flange 12 and a vertical rib member 14. Normally, the cross member flange 12 would butt up against the side of the flange 4 of the main runner. Herein, the flange of the cross member is provided with a bent-up lip 16 which slightly overlies the upper surface of the flange 4 of the main runner. When looking at the suspended ceiling system from the floor area of the room, the two horizontal flanges tend to blend together to form aneat appearing joint. It is possible to eliminate the lip and just make the cross member flange higher than the main runner flange.
Normally, a tab element 18 which is bent out at a angle from the longitudinally extending axis of the cross member 11 would slide into the fastening means 8 of the main runner. Shoulders 19 position the tab adjacent one side of the fastening means 8. A small dimple 20 on the cross member tab coacts with a small dimple on the main runner rib 6 to provide a positive friction lock to prevent the tab from readily sliding out from the fastening means 8. The structure 22 interconnects the tab 18 and the rib portion 14 of the cross member. This element 22 is formed with a corrugated structure as best shown in FIG. I.
When there is a fire in the room below the ceiling system, the heat from the fire will cause the cross member to expand in the direction 24 shown by the arrow in FIG. I. The expansion of the cross member is compensatedfor by a collapsing of the corrugated structure 22 which now permits the expansion of the main portion of the cross member. The lip 16 lets the horizontal flange of the cross member ride up over the horizontal flange of the main runner member. Since the structure exists at both ends of the cross member, the 24 inches long cross member is provided with the capability of expanding upwards to one-half inch, which is more than adequate in normal circumstances. Since the cross member now expands without buckling or without pushing two parallel main runners apart, the ceiling boards are now held in place in the suspension system during a fire.
What is claimed is:
l. A ceiling suspension system in the form of a grid comprising uniformly spaced main runner members extending parallel to each other, a series of cross members extending between the main runner'members to define the grid pattern, the improvement comprising an expansion ioint for connecting together the cross member to the main runner member, the joint comprising a fastening means on the vertical rib of the main runner and a tab on an extension from the vertical rib of the cross member, the extension between the main body of the vertical rib of the cross member and the tab being corrugated with the folds of the corrugations being transverse to the longitudinal axis of the web, said tab being connected to the fastening means of the main runner to connect the main runner and cross member together and the corrugated structure permitting, through its collapsing, the expansion of the cross member under the application of heat.
2. The structure of claim 1 wherein the horizontal flange of the cross member is provided with a lip which overlies the upper surface of the horizontal flange of the main runner member so that the flange of the cross member will slide up over theflange of the main runner member when the crossmember expands due to the influence of heat.
3. The structure of claim 2 wherein the fastening means on the main runner member vertical rib is a dual
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|Citing Patent||Filing date||Publication date||Applicant||Title|
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|EP1703034A1||Mar 18, 2005||Sep 20, 2006||Chicago Metallic Continental||Ceiling suspension system|
|WO1999053584A1 *||Feb 4, 1999||Oct 21, 1999||Efraim Molek||Interlocking modular ladder-type cable tray|
|U.S. Classification||52/232, 403/2, 52/664, 403/230|
|International Classification||F16B7/04, E04B9/12, E04B9/06|
|Cooperative Classification||F16B7/0486, E04B9/127|
|European Classification||F16B7/04D4E, E04B9/12D|