Abstract:
Improved electrochemical-grinding apparatus and method whereby the accuracy of reproduction of the electrode contour in the workpiece is sharply increased by limiting the thickness of the electrolyte film carried by the grinding wheel to a minimum. The film thickness is reduced by a scraper or wiper held against the wheel, by directing a stream of high-velocity air thereagainst to dissolve the excess electrolyte, and/or by electrochemically reforming the electrolyte. The wiper may serve as an electrode for the re-formation of the electrolyte film or as the nozzle for the jet of air and is contoured complementarily to the wheel by electrochemical action or casting thereagainst. Both the wheel and the electrode are preferably composed of graphitic materials.
Abstract:
A method of coating a substrate in which a mass of particulate material is formed in situ or disposed between a pair of electrodes which produce a spark discharge to create a shock wave carrying the particles onto and bonding them to the substrate. The particles are activated by their presence within the discharge.
Abstract:
A method of decreasing the sulfur content of crude oil and other petroleum products in which the sulfur is present in an elemental state or in chemical combination with an organic substance (i.e., the crude oil), in which high-energy activation at relatively low temperatures ruptures carbon-sulfur bonds of the molecules and effectively forms hydrogen-sulfur bonds in the form of H2S or carbon-sulfur bonds as CS2, etc. so that gaseous sulfurcontaining compounds are evolved from the liquid. The periodic high energy can be an impulsive spark discharge alone or accompanied by vibrational shock of sonic or ultrasonic frequency; laser activation with or without sonic waves of a frequency facilitating the rupture of the bonds to produce gaseous sulfur-containing compounds is also suitable. The apparatus includes an activation chamber through which the crude oil is pumped while being transported aboard a tanker or the like, means for recovering or discharging the gases, and one or more sulfur-removing devices such as a spark-discharge electrode assembly, cavitation generator, ultrasonic or sonic transducer, shock wave generator, high frequency electrode assembly, laser or microwave generator.
Abstract:
Method of making an electrode for the electrochemical machining or the electric discharge machining of a metallic workpiece, especially for the production of a number of substantially identical electrodes adapted to be used for the serial machining of numerous workpieces, wherein an electrode blank in the form of a metal sheet is placed over a die having a contour corresponding to that of the finished-body shape and is conformed to the die by high-energy-rate forming with a shock wave generated by spark discharge (see U.S. Pat. Nos. 3,208,254 and 3,232,088). When the electrode is used for the electric discharge machining of a workpiece, a thin spacing layer is applied along its surface juxtaposed with the die prior to spark forming and is thereafter removed so that the overlying metal body constitutes a roughforming electrode designed to shape the contours initially. The finish-forming electrode may be formed simultaneously, e.g. as the spacer layer.
Abstract:
Dental cement with superior crushing strength is made from (1) one or more of zinc oxide, silicon oxide, and aluminum oxide, containing conventional additives, if desired, (2) 0% to 20% of a fluoride such as calcium or sodium fluoride, (3) phosphoric acid, diluted and containing additives, if desired. To impart the superior crushing strength, these ingredients are spatulated while applying an electric field across the mixture, either direct current alone, or preferably, direct current on which is superimposed a high-frequency alternating current. The resulting cement is much stronger, adheres better to teeth, and reduces the development of bacteria.
Abstract:
A measuring instrument comprising body member having a first surface and a second surface movable relatively to said first surface, an electro-optical display mounted on said body member for displaying a distance between said surfaces measured in numeric form, a transducer responsive to the relative movement between said surfaces for producing pulses representative of the distance travelled in said relative movement, and a large-scale integrated circuit mounted on said body member, said integrated circuit including at least a portion of said transducer, an updown counter coupled to said transducer for receiving the output pulses thereof and a decoder driver coupling the output of said up-down counter to said electro-optical display for digitally signalling said distance measured.
Abstract:
A heat exchanger is formed by compacting metallic particles, especially of materials of high thermal conductivity to form the heat exchange surfaces, preferably against a substrate such as thermally conductive tube. The compaction involves electrical sintering, with the particle-particle interfaces and the particle-substrate interfaces metallurgically homogenized to form a monolithic structure free from corrosion sites.