Abstract: A drywall furring system comprises a plurality of longitudinal carrying channels having congruent tongues co-planar with, spaced apart along and depending from the opposite flanges of the channels and a plurality of furring channels having pairs of slots spaced apart along the opposite flanges thereof. On opposite edges of the tongues there are tabs tapering upwardly from the rounded corners thereof and elongated, narrow fingers whose lower margins angle up from a point space apart from the distal edges of the tongues. The tabs and fingers have seats in the same horizontal plane and the fingers have retaining hooks extending up beyond the seats. A gridwork of the carrying channels and furring channels is constructed by aligning opposed congruent fingers of the former with a pair of slots in the latter and passing the fingers through the slots and pushing the opposite flanges of the furring channel over the rounded corners of the tongues so that the furring strips rest on the seats of the fingers and tabs.

Abstract: A method for producing a lightweight set cementitious product having excellent strength by forming a aqueous cementitious slurry, incorporating therein expandable polystyrene beads which are less than completely expanded, and heating the slurry to drive off excess water, to cause a cementitious mixture to set, and to further and completely expand the polystyrene beads. In a preferred embodiment and aqueous slurry of calcium sulfate hemihydrate is produced including expandable polystyrene beads in a state which they are partially but not fully pre-expanded. The slurry is deposited between two paper cover sheets, and the product is heated to drive off excess water, to set the gypsum to the solid dihydrate state, and to complete the expansion of the polystyrene beads until they reach their fully expanded state, thereby resulting in a strong lightweight gypsum wallboard which has excellent adhesion between the expanded polystyrene beads and the set gypsum.

Abstract: A buckle-resistant resilient runner having a thickness of from 0.017 to 0.020 inch is interposed between the framework and the wall-board of a partition having a sound transmission coefficient of 53. A scalloped web connects the wallboard support flange and the flange of the runner which is fastened to the framework. The distance between the support flange and a notch in the scalloped web is equal to or greater than the width of a stop flange on the opposite edge of the support flange. This design makes the runner much more resistant to buckling than a prior art runner made from thicker sheet metal.

Abstract: Gypsum is calcined by contacting it with the hot gases spewing out of a combustion tube submerged in the mass of gypsum. The formation of dead-burned anhydrite is reduced by surrounding the combustion tube with a second tube called a draft tube. Gypsum passing through the annulus between the tubes is heated by the hot gases and is ejected from the annulus to prevent repeated excursions into the hot gas zone at the muzzle of the combustion tube.

Abstract: Hydrodynamic pumping of the fluidized calcining mass in a kettle is set up by the continuous flow of the mass to and from heating rods immersed therein which are constantly emitting at least about 1 British Thermal Unit of heat per minute per square inch of the surface of the rods. The transfer of heat from the walls and bottom of the kettle is enhanced so that more of the available heat is actually absorbed than in a kettle lacking such heating rods. The rate of calcination may be increased while the rate of heat input is decreased.

Abstract: The unequal porosity and different textures of a drywall reinforced with joint tape and joint compound are concealed by a paint made from a low cost, easily dispersible powder in which the pigment volume concentration is about 70% to about 75%. A vinyl acetate/ethylene copolymer serves as the principle binder and a water soluble cellulose ether thickens the water dispersion of kaolin, attapulgus clay, mica, sodium potassium aluminum silicate and calcium carbonate.

Abstract: Apparatus and method for rotary buffing or wiping of workpieces having uneven surfaces in which the workpiece generally linearly advances relative to one or more buffing rolls which are spinning about spin axes disposed in a plane generally parallel to the workpiece surface and simultaneously rotating about an axis generally perpendicuar to the workpiece surface. In a preferred embodiment, the buffing rolls are supported in a rotating carriage with their spin axes in coparallel relationship.

Abstract: A walkway on a rooftop comprises expanded metal planks supported by U-shaped support stands disposed transversely with respect to the length of the planks. The planks have alternating rows of ridges and valleys, both of which have transverse slits. The planks are connected to the support stands by T-shaped bolts whose crossbars are rounded. The shanks of the T-bolts pass through the slits in the valleys and the crossbars nestle within the valleys in rotatably slidable engagement with the metal.

Abstract: An intersection spacer is disclosed for use in a subceiling structure of a grid of open-ended runner beams and intersecting open-ended cross beams, the intersection spacer being generally square in horizontal cross section with inverted vertical corner edges forming four outwardly directed protrusions adapted to engage within the beam ends. A top plate on the spacer bears the weight of the ceiling. A bottom cap on the spacer carries a decorative panel. The spacer may be made of two identical mating halves. A method of assembling a subceiling with such intersection spacers is also disclosed.

Abstract: Large, dense chromic oxide refractory blocks containing from about 80% to about 98% chromic oxide are made by firing a green block comprising, in addition to the chromic oxide, titania and a colloidal silica having a surface area of at least about 90 m.sup.2 /g. Blocks having porosities as low as 0% are made in either an oxidizing or a reducing atmosphere. The blocks are crack-free and have a good resistance to corrosion by molten glass.

Abstract: A generally L-shaped coupling plate having an arcuate mandrel at the junction of two generally rectangular tongues is united with a notched out channel by inserting the first tongue into slots defined by the web of the channel and opposed ribs spaced apart from and parallel to the web, bending the notched out portion of the channel around the mandrel, and inserting the second tongue of the plate into the slots of the bent portion of the channel as it approaches the plate. Barbs on the edges of the plate dig into the channel to secure the union of the two pieces. The channel may be painted before being bent around the plate so that a predecorated rounded corner runner may be installed at the intersection of two partitions.

Abstract: Hang-on furniture supporting studs standing independently at the intersection of wallboard partitions are tied together by an intersection stud for proper orientation and stabilization.

Abstract: An adjustable, U-shaped support stand is disposed transversely between an expanded metal walkway and a roof so that the walkway may be made level although the roof slopes or may be inclined with respect to the roof. The support stand has a U-shaped base comprising a foot, a short leg and a long leg, each leg having spaced apart columns of holes. Connected to each leg are extensions having an oval slot and a hole spaced apart in accordance with the columns of holes on the legs. Alignment of the slots and holes in the extensions with the appropriate holes in the legs allows the extended legs to be of different heights with respect to each other and also allows one end of an extended leg to be higher than the opposite end. The expanded metal walkway may thus be levelled even though the roof slopes in both the lateral and longitudinal direction under the walkway.

Abstract: Expanded perlite coated with a composition to render the perlite impervious to water, and a joint compound incorporating the same. The perlite is ground prior to expansion to provide subsequently expanded perlite having a mean particle size from about from about 50 to about 70 microns, the joint compound formed from the perlite having greater uniformity in paint gloss appearance between the painted surface of the joint compound and the painted surface of the gypsum wallboard on which the joint compound is applied.

Abstract: A setting accelerator for calcined gypsum plaster and a process for its preparation are disclosed. The accelerator comprises finely ground calcium sulfate dihydrate having composite coatings on the particles of firstly a calcination inhibiting material such as sugar and secondly a coating of aluminum sulfate hydrate. The accelerator is particularly useful in the formation of gypsum wallboard.

Abstract: A valve apparatus for the precise regulation of a stream of molten material such as molten rock or slag as it issues from a primary melter or holding device, comprising a frame retaining a valve, the valve comprising a pair of plate-form valve members, one fixed and one movable with respect to the other, each having an aperture or orifice provided therein. Maximum rate of discharge occurs when the apertures are in juxtaposition, and flow cut-off occurs when the apertures are not in juxtaposition. Power operated means is provided for the movable valve member to obtain proper stream regulation or complete cut-off. The apertures are so contoured that, as the valve is moved toward closed position, the cross-sectional shape of the effective opening and the flowing stream of molten material remains substantially uniform and unchanged.

Abstract: An integral generally channel-form runner for securing and supporting one or more wallboard panels in a demountable structure, the runner having an integral support for the lower edges of the wallboard panels in a position spaced above the bottom of the runner to prevent absorption of water and formation of mildew at the edges of the wallboard panels.