Abstract: A sag resistant, cast acoustical ceiling tile which has a mineral wool core and a starch binder and which has a formaldehyde resin impregnated paper backing. A kraft paper backing which has been impregnated with a melamine formaldehyde resin has been found particularly effective in providing sag resistance in high temperature, high humidity conditions such as encountered in Pacific Rim countries. A method has been developed to manufacture the sag resistant, cast acoustical ceiling tile wherein water is applied to the paper backing prior to machining and painting to provide a tile which has a relatively flat initial plane position.

Abstract: A suspended ceiling grid system with an integrated aperture for accessories such as lights, air diffusers and like accessories. The system has an appearance ring of suitable size that forms the aperture and that interconnects with runner elements of corresponding suitable length. The ring is disposed at the geometric center of a grid module and the interconnected runners are arranged to provide support for the ring and related accessory.

Abstract: A connector for suspended ceiling grid that provides a first end lock in a main tee slot and a lock with an identical opposed connector. The connector in the first end lock and in the connector-to-connector lock is installed with a simple stab-in motion. The connector works with a non-re-entrant slot profile that avoids the risk of improper assembly. The connector is releasable without tools and is reusable. The connector emits an audible click when fully installed, is resistant to damage from rough handling, and affords high tensile and compressive strength in its connections.

Abstract: A panel access clip for relocatable partitions having a snap-engageable part struck-up from a base portion over a central cut-out and joining said base portion at a flexure zone spaced inwardly from a panel engaging portion of the clip, whereby to reduce shear forces on the panel edge and locate the point of bending flexure during engagement and disengagement with a support member to a zone spaced at least one-half the width of the clip from said panel engaging portion. The clip being capable of allowing engaged panels to be removed from a wall partition assembly without damage to the edges of the panel, whether they are kerfed or non-kerfed panels.

Abstract: An apparatus for producing a fissured, acoustical ceiling panel wherein the pins used to fissure the panel are roll applied thereto. The pins are embedded in flexible, resilient polymeric plates, and a plurality of the plates are attached to a rotary drum which is used to apply the fissuring pins to the surface of the panel. The invention also includes the method for manufacturing the polymeric plates which are molded and formed with the fissuring pins embedded therein.

Abstract: An acoustical tile composition based on a gypsum/cellulosic fiber composition which can replace all or a portion of the mineral wool normally present in acoustical ceiling tiles. The gypsum/cellulosic fiber composition is combined with a lightweight aggregate material and a binder to form a composition which is used in a water-felting process to manufacture acoustical ceiling tiles and panels. The preferred source of the cellulosic fiber is a composite gypsum/cellulose fiber material which is prepared by mixing the gypsum and cellulosic fiber material with sufficient water to form a dilute slurry which is then heated under pressure to calcine the gypsum, converting it to an alpha calcium sulfate hemihydrate. The resulting composite material comprises cellulosic fibers physically interlocked with calcium sulfate crystals. Another source of both gypsum and cellulosic fibers is waste (scrap) gypsum wallboard. Expanded perlite is the preferred lightweight aggregate material.

Abstract: A connector for suspended ceiling grid that provides a first end lock in a main tee slot and a lock with an identical opposed connector. The connector in the first end lock and in the connector-to-connector lock is installed with a simple stab-in motion. The connector works with a non-re-entrant slot profile that avoids the risk of improper assembly. The connector is releasable without tools and is reusable. The connector emits an audible click when fully installed, is resistant to damage from rough handling, and affords high tensile and compressive strength in its connections.

Abstract: A mineral wool-free acoustical tile composition and the acoustical tile made therefrom wherein an expanded perlite is used as a substitute for granulated mineral wool to provide porosity and good sound absorption properties. It is preferred that the composition and acoustical tile also contain an inorganic filler to provide texturability during the manufacturing process. In addition, the acoustical tile composition also contains a starch gel binder and a fiber reinforcing agent selected from the group consisting of cellulosic fibers, polymeric fibers and glass fibers. It has been found that the mineral wool-free acoustical tile compositions of this invention have acoustical properties comparable to the commercially available cast mineral wool tiles. In addition, the mineral wool-free compositions can be used to cast an acoustical tile using equipment and procedures currently used to produce cast mineral wool tiles.

Abstract: The manufacture of sag-resistant, lightweight structural mineral panels on a foraminous support wire is accomplished by forming a dilute aqueous dispersion of mineral fiber and/or aggregate and an anionically stabilized latex binder, coupling the binder solids onto the mineral fiber materials by adding a small amount of a flocculant such as a cationic polyacrylamide, and passing the slurry onto a first flooded section of the support wire to form an open, entangled, structural mass having water in interstitial spaces of the entangled mass. Water is stripped from the mass and the mass dried without collapse of the open structure by passing heated dry air through the open entangled structure.

Abstract: An end connector structure for suspension ceiling grid systems provides a connector to connector lock on each side of the web of a through runner. The lock includes a lateral tear drop shaped protrusion providing a rearwardly facing exposed edge in combination with a lateral strap on an associated identical connector which also provides a rearwardly facing exposed edge. When tensile stresses are applied between the two connectors, the connector to connector lock is subjected to forces causing the associated rearwardly facing edges to engage and resist connector separation. The protrusion joins the adjacent portion of the connector material with bends having relatively large radius of curvature to reduce the weakening of the structure of the protrusion resulting from notch sensitivity. These large radius of curvatures result in substantially improved ultimate strength in the connector to connector lock when compared with protrusions formed with relatively sharp bends.

Abstract: A support system for trimming exposed edges of suspension ceilings provides a trim strip mounting clip which mounts on the bulb of an adjacent grid tee member and provides a face portion which snaps into and locks with a channel-shaped trim strip. The connector clip supports the trim strip from the adjacent grid members without any exposed fasteners and provides an uninterrupted finished edge appearance. Several embodiments of connector clips are illustrated, one of which provides a support portion pivotally connected to a face portion so that trim strips can be mounted on adjacent grid members in positions parallel to the adjacent grid members and at angles relative thereto. Also disclosed are splice plates which bridge between abutting ends of trim strips to lock such abutting ends in proper alignment. Such splice plates can be used with straight or curved trim strips and can also be used at inside corners.