Abstract: There is disclosed herein a hearing protector structure comprising a generally U-shaped spring headband and a pair of ear canal obturating elements articulatingly affixed to the end portions of the headband. The hearing protector of the invention is possessed of the characteristics of light weight and comfort combined with superior sound attenuation performance.
November 29, 1982
Date of Patent:
July 24, 1984
Ross Gardner, Jr., Robert N. Falco, John P. Stallings
Abstract: An electroslag remelting process for manganese-base alloys. The process includes the steps of: partially immersing a consumable electrode of a manganese-base alloy in a layer of molten slag and passing current between the consumable electrode and a second electrode. The current is passed through the slag layer under conditions which gradually melt the consumable electrode so that drops of molten metal from the consumable electrode move downwardly through the slag layer and resolidify as an ingot thereunder. The slag is characterized by a fusion temperature of more than 300.degree. F. (149.degree. C.), and often more than 350.degree. F. (177.degree. C.), above the melting point of the consumable electrode. It is preferably comprised of Al.sub.2 O.sub.3, CaO and CaF.sub.2.
Abstract: A composite article having particular utility as a welding stud and a process for producing the article. The article is comprised of a pin and an enclosing member formed from a dissimilar material. The pin is comprised of a head and a shank. The pin is formed from a metal. The cross-section of the head is larger than that of the shank in a direction normal to the length of the pin. The enclosing member fits over and is adhered to the shank. The enclosing member is formed from material in powder form. It is placed upon the shank and sintered thereon. The enclosing member fits up against the head so that the article is substantially devoid of a gap therebetween. The absence of a gap is attributable to the shape of the shank. The cross-section of the shank is larger, in a direction normal to the length of the pin, adjacent the head than over other parts thereof.
Abstract: There is disclosed an improved process and apparatus for the production of finely-divided metal and metalloid oxides by flame hydrolysis of corresponding metal and metalloid halides whereby fouling of burner apparatus is substantially completely avoided.
Abstract: Disclosed is a process for recovering chromium, vanadium, molybdenum, and tungsten from secondary resources such as alloy scrap comprising a refractory metal and base metals such as cobalt, nickel, iron, and copper. The scrap is calcined with sodium carbonate in air to convert the refractory metal values to MoO.sub.4.sup..dbd., VO.sub.4.sup..tbd., WO.sub.4.sup..dbd., and CrO.sub.4.sup..dbd. and the base metals to water insoluble oxides. A leach of the calcined materials produces a pregnant liquor rich in refractory metals which, after separation of the vanadium, molybdenum and tungsten values, is treated with CO, CHOO.sup.-, CH.sub.3 OH, or HCHO to reduce Cr.sup.+6 to Cr.sup.+3. The carbonate and bicarbonate salts produced as a byproduct of the reduction are recycled to the calcination stage.As a result of the V, W, and Mo partition, a mixed solid comprising CaO.nV.sub.2 O.sub.5, CaMoO.sub.4, and CaWO.sub.4 is produced.
April 15, 1980
Date of Patent:
July 14, 1981
Alkis S. Rappas, Jameel Menashi, Donald A. Douglas
Abstract: Relatively high pressure mixtures consisting essentially of a major ethane component and a minor, but substantial, propane component are separated into relatively pure ethane and propane fractions by subjecting such mixtures to a number of specific cooling steps and an expansion step preparatory to and in combination with a fractional distillation step. The overhead ethane fraction of the method has a propane content of no greater than about 10 mole percent and is provided in the gas phase. The propane bottom fraction of the method is provided in the liquid phase.