Ceiling grid with seal

• US 6,701,686 B1
• Filed: 01/16/2003
• Issued: 03/09/2004
• Est. Priority Date: 01/16/2003
• Status: Active Grant

• Current Assignee: Worthington Armstrong Venture
• Original Assignee: Worthington Armstrong Venture
• Inventors: Platt, William J.
• Primary Examiner(s): Brown, Peter R.
• Application Number:
  US10/346,039
• Time in Patent Office: 418 Days
• Field of Search: 525/060.7, 527/317, 527/331
• US Class Current: 52/506.07
• CPC Class Codes: E04B 2009/062 Caps covering visible surfaces of the supporting construction
• CPC Class Codes: E04B 9/02 having means for ventilation or vapour discharge
• CPC Class Codes: E04B 9/067 with inverted T-shaped cross-section
• CPC Class Codes: E04B 9/068 with double web
• CPC Class Codes: E04B 9/242 with separate retaining elements

Abstract

A beam for a suspended ceiling in a clean room has soft plastic flaps on top of the flanges. The flaps form a seal when a ceiling panel is supported on the beam. The flaps, formed continuously as the beam emerges from a roll forming operation, are integral with a plastic coating on the metal beam core.

Claims

1. In a grid beam (22) for a suspended ceiling comprising

a) an inverted T cross section of steel forming a core (26) having a web (27), and flanges (28,29) extending horizontally from the web (27);

the improvement comprising

b) a coating (30) on the flanges (28,29); and

,

c) flaps (33) of soft flexible plastic integral with, and extending diagonally upwardly from the coating (30) on the flanges.

2. The beam 22 of claim 1, wherein the coating (30) is of a hard plastic.

3. The beam (22) of claim 1 or 2, wherein the flaps (33) have a bead (36).

4. The beam of claim 1 or 2, wherein the flaps (33) yield to form a seal (40) when a panel (23) is laid on the flange (28,29) of the beam (22).

5. The beam of claim 1 or 2, wherein the web (27) has a stiffener (31) of hard rigid plastic at the top thereof.

6. The beam of claim 1 or 2, in combination with flaps (43), integral with a coating (45) on the web (27) of the beam, extending diagonally outwardly from the web (27).

7. In a method of making grid beams (22) for a suspended ceiling (20) having an inverted T-shaped cross section with a vertical web and horizontal flanges extending outwardly from the web,

a) continuously forming the beam (22) from a roll of flat steel through a series of roll stations,

the improvement comprising

as the beam continuously emerges from the roll forming stations,

b) continuously forming, in an extrusion station, a coating (30) of plastic on the flanges (28,29) of the beam (22),

c) continuously forming flaps (33), integral with the coating (30), on the upper surfaces of the flanges (28,29), in the extrusion station, of a plastic softer and more flexible than the coating (30).

8. The method of claim 7 wherein the coating (30) hardens after the flaps (33) are applied.

9. The method of claim 7, wherein the plastic is PVC.

10. The method of claim 7 wherein additional flaps (43) are formed on the web of the beam.

11. A grid beam (22) formed by the method of claim 7, 8, 9, or 10.