Abstract: An acoustical panel formed from a fibrous, open-celled material comprised of up to about 50% by weight fibers, between about 3% and about 10% by weight binder, between about 20% and about 75% by weight filler and about 0.01% to about 2.0% by weight surfactant. Additionally, voids are formed within the panel having an average distribution size diameter of about 50 &mgr;m to about 250 &mgr;m. The acoustic panel achieves very high sound absorption properties without the need for additional surface perforations, while maintaining a very high surface hardness.

Abstract: The grid member is formed of sheet metal and has an inverted T-shape with a bulb at the top, a double thickness central web and oppositely disposed flanges at the bottom. To achieve controlled expansion, an extended angular lance is cut at the top of the bulb. Further, staggered cutouts are placed in the two thicknesses which make up the web. By staggering the cutout areas of adjacent web layers, the overall web strength is maintained. These web cutouts and the lance at the top of the bulb cooperate upon thermal expansion, causing the bottom flanges to buckle down, and the web and bulb to separate laterally and fold. The folded web configuration directed by the staggered cutout pattern will maintain longitudinal rigidity.

Abstract: The grid member is formed of sheet metal and has an inverted T-shape with a bulb at the top, a double thickness central web and oppositely disposed flanges at the bottom. To achieve controlled expansion, two parallel lances are cut along opposite sides of the bulb near the top of the bulb. No metal is removed at this area of maximum bending stress. Further, staggered cutouts are placed in the two thicknesses which make up the web. By staggering the cutout areas of adjacent web layers, the overall web strength is maintained. These web cutouts and the lance at the top of the bulb cooperate upon thermal expansion, causing the bottom flanges to buckle down, and the web and sides of the bulb to separate laterally and fold, and the top of the bulb to buckle up. The folded web configuration directed by the staggered cutout pattern will maintain longitudinal rigidity.

Abstract: A suspended ceiling system is provided with a ceiling runner arrangement and ceiling boards positioned therein. At the intersection of four runners and ceiling boards, a cutaway area can be provided in the board structure to receive a decorative element. A new ceiling design is formed from the decorative element(s) used in conjunction with the ceiling boards.

Abstract: The invention provides a slot in the runner and lugs on a clip to allow sliding contact between the runner and the clip. This allows for expansion of the runner during a fire condition. The clip is fastened to the vertical web of an adjacent runner to fasten the runner structures together. Normally, a clip is provided on each end of one runner structure and it is mounted between two rigidly positioned other runner structures and the runner with the clips is capable of expansion and contraction under fire conditions without buckling.

Abstract: The invention is directed to a ceiling runner which has a generally U-shaped configuration. The runner has flanges to support ceiling boards. The side walls of the runner are formed with grooves which may be used to support the runner in position or define an isolated chamber within the body of the runner. The side walls of the runner have a second groove which is used for positioning ceiling boards on the flanges.

Abstract: Suspended ceiling systems are formed from a series of modules which may have a vaulted design and a light fixture therein. These modules must be supported from the main runners or cross tees of a suspended ceiling system. The support structure herein is fastened at one end to the main runners or cross tees of the suspended ceiling system and carry on their other end the main horizontal support members for the light fixture and vaulted module. Means positively lock the support structure to the main runner or cross tee of the suspended ceiling system.

Abstract: An end detail is provided for a cross tee to provide positive engagement of the cross tee with the main runner of a suspended ceiling system. The end detail of the cross tee may be provided with means which will positively lock the tee in place to bracket-like structures on the main runner. The positive locking, yet removable, fastening means is provided to fasten the cross tee to the main runner of a suspended ceiling system.

Abstract: Suspended ceiling systems are formed from a series of modules which may have a vaulted design and a light fixture therein. These modules must be supported from the main runners or cross tees of a suspended ceiling system. The support structure herein is fastened at one end to the main runners or cross tees of the suspended ceiling system and carry on their other end the main horizontal support members for the light fixture and vaulted module.