Abstract: A dental restoration fabricating device in which dowels are employed to locate and register teeth and teeth dies. The dowels are held in their original positions by plastic holders arranged on an adjustable fence surrounding a base which, in turn, supports an impression of the patient's mouth. An alternate form includes an alignment pin for more accurate location of the tooth dies.

Abstract: A system of generating electric power derived from the energy of the sun, the atmosphere, the ground or the heat stored in ground water, whichever provides the greatest temperature differential with another adjacent source of energy. During the daytime when the sun is shining, a solar absorber composed of a plurality of black pipes may provide the heat necessary to generate power. At night when the air temperature is lowered, a set of pipes in the ground or in a lake may provide the heat necessary to extract power by using the low temperature of the environment. A third source of heat such as geothermal heat, stored heat or a heat pump may be part of the system. Switching means are used to convert from one system to another depending upon which system has the greatest temperature differential.

Abstract: Precision investment casting of small parts with fine detail and free of air inclusions is achieved by the use of flat sided blocks of a relatively high melting point plastic material received upon elongated tubes or rods of the same or similar material. The shape and size of the blocks permit a large number of small parts to be cast at the same time and provide reservoirs for the molten casting metal close adjacent the casting cavity.

Abstract: A circuit is described for operating on a carrier wave in a transmission signal including a reduced carrier with a single sideband. The carrier wave is isolated, limited, divided in frequency by a predetermined amount, and then restricted in frequency by a band pass filter. The output of the band pass filter is then multiplied in frequency. After this, the carrier wave is mixed with the sideband frequencies and the signal is demodulated.

Abstract: Aligned hollow knuckles on a pair of hinge leaves form a cylindrical barrel. Spaced plugs inserted into each end of the barrel serve to keep the knuckles from separating and act as a pivot pin for the hinge. Bifurcated reduced inner portions of the plugs receive the ends of a coil spring therebetween. One plug is permanently secured to a knuckle of one hinge leaf. A pin secured to the other knuckle extends into the barrel and is carried within an annular groove in the adjacent plug. A stop in the groove limits the travel of the pin. Minimum tension is provided at all times in the hinge by the initial setting of the stops with respect to the pin. Additional tension is provided by a plug rotating means together with a second pin engageable with recesses in the plug and a bore in the hinge knuckle.

Abstract: Disclosed herein is a synthesis of ortho chlorobenzalmalononitrile by reacting malononitrile with ortho-chloro benzaldehyde in methanol in the presence of a basic catalyst; separating the product crystals from the methanol; washing the crystals with fresh methanol; combining the wash methanol with the methanol filtrate and using the combined methanol in another similar synthesis run and repeating a series of such runs; drying the crystals with a current of turbulent dry air and scrubbing the air with base solution thereby substantially reducing associated problems of effluent treatment and ambient air pollution.

Abstract: A machine for continuously scoring and slitting paper, such as corrugated board and the like and for changing the pattern of cuts and scores while the paper is in motion. Two sets of scoring and slitting rollers having a plurality of scoring and slitting assemblies thereon are used, only one of which is in use at any time. The inactive set of rollers can be adjusted and secured in a new cutting pattern while the other set is operating. The scoring and slitting assemblies on the rollers are moved into position by a common threaded rod. Each roller, scoring or slitting assembly, is provided with a split nut and an electrically controlled clutch which is used to engage the nuts and to move the roller assemblies selectively along the threaded rod to a desired cutting position.

Abstract: A charged aerosol device for air purification and other uses. Droplets from a capillary tube are passed through an electric field having an intensity just below breakdown. The droplets are thereby broken into minute particles and produce a fine spray. The resulting large surface area of the spray absorbs noxious gases within the range of a 6th power law. By adjusting the flow rates to an optimum value, the device can be made to generate electric power in excess of that needed to operate the apparatus. A flow of clean dry air is introduced around the aerosol capillary tube and charging electrode to eliminate the possibility of electrode fouling and shorting. High temperature exhaust gases, in another arrangement, are first partially cooled before introduction to the charged aerosol.

Abstract: Sulfidic ores of lead or zinc such as galena or sphalerite are smelted under vacuum in the absence of CO.sub.2 and oxygen with a flux consisting of solid NaOH or KOH to free the lead or zinc as free metal and to form sodium or potassium disulfides which are used as flux in smelting additional sulfidic ores to liberate more metal and form still higher polysulfides of sodium or potassium also usable as flux up to the pentasulfide form. By the process of the invention, substantially complete use is made of the sulfur atoms initially combined with the lead or zinc to remove the sulfur combined with said metals. Potassium hydroxide, its lower sulfur content polysulfides can be reconstituted by exposing to air a leach solution of potassium pentasulfide.

Abstract: A fixed cutting blade is received within one end of a two part housing. An elongated guard having a U-shaped cross section embraces the housing parts at the blade end and is shiftable through a series of positions to expose different amounts of the cutting blade including a blade covering or "safety" position.

Abstract: Copper is recovered from its sulfidic ores by a process wherein the ore is mixed and fused with at least a stoichiometric amount of a sulfide of sodium or potassium which may be prepared in situ by reacting sulfur with potassium or sodium hydroxide. The mixture is heated under vacuum in the absence of water, oxygen and CO.sub.2 to a temperature above the melting point of the selected potassium or sodium sulfide and maintained below the decomposition point of the sulfide for a time sufficient to cause the sodium or potassium sulfide to combine with the sulfur of the copper sulfide to form metallic copper and copper oxides and the higher (sulfur content), sulfides of sodium or potassium, the resulting melt is cooled and leached with cold water to remove the sodium or potassium polysulfides and leaving behind metallic copper and copper oxides. The polysulfides can be recovered and recycled. The preferred unsaturated sulfides are sodium trisulfide and potassium tetrasulfide.