Abstract: A pneumatic air feed peck drill adapted to drill in repetitive cycles including a rapid advance phase, a slower drilling phase, and a rapid retract phase. The rapid advance phase ends and the drilling phase begins at a set back position, an adjustable distance from the workpiece, to minimize a drill bit and workpiece damage. The drill includes a drill motor and feed cylinder powered by air to rotate and advance and retract the drill motor. The drill motor and feed cylinder is coupled with an air and mechanical control system including a hydraulic feed control unit having a piston rod coupled with the drill motor to dampen the advance of the drill motor during the drilling phase and to release for rapid retract and advance phases.

Abstract: A burned chrome-containing refractory and method which provides a refractory having less than 5 ppm total soluble chromium. Such product is obtained by adding to the starting mix less than 10 wt. % (often less than 3 wt. %) zirconia, silica, zircon, or molybdic oxide either individually or in combination.

Abstract: A method for measuring the weight of a suspended load, such as the bucket of a dragline, is disclosed. The method incorporates visual observations by a person such as a test engineer, or the operator of the dragline. During a dig cycle, once the steady state operation of the hoist is achieved, sampling of parameters such as hoist motor armature and field currents, and hoist and drag rope lengths, is performed. Using the calculated values of the force applied to the load and the geometry determined by the various rope lengths, the weight of the suspended load is calculated for each sample in the dig cycle. The calculated weight data may be accepted or rejected based upon the presence of dynamic factors observed by the test engineer or operator, or evident in the data. Calibration of certain values, such as the hoist efficiency, may take place on-site, rather than relying on theoretical or modeled values.

Abstract: A pneumatic air feed peck drill adapted to drill in repetitive cycles including a rapid advance phase, a slower drilling phase, and a rapid retract phase. The rapid advance phase ends and the drilling phase begins at a set back position, an adjustable distance from the workpiece, to minimize a drill bit and workpiece damage. The drill includes a drill motor and feed cylinder powered by air to rotate and advance and retract the drill motor. The drill motor and feed cylinder is coupled with an air and mechanical control system including a hydraulic feed control unit having a piston rod coupled with the drill motor to dampen the advance of the drill motor during the drilling phase and to release for rapid retract and advance phases.

Abstract: The present invention provides an as-fired, high alumina, low silica, corrosion resistant, refractory product and a method for making said product where the product includes from about 50 wt. % to about 80 wt. % of a bubble alumina, from about 10 wt. % to about 30 wt. % of a fine calcined alumina and from about 5 wt. % to about 20 wt. % of a fine hydrated alumina. The product is characterized by having an alumina content of at least 98 wt. % alumina, a silica content of less than 1 wt. %, a density of from about 80 to about 95 pounds per cubic feet, a porosity of from about 55% to about 65%, a room temperature modulus of rupture of at least 200 psig and a cold crushing strength of from at least 200 psi.

Abstract: A refractory composition consisting essentially of, for each 100 wt. % thereof, about 40 to 80 wt. % of an alumina, about 5 to 30 wt. % of a zirconia-containing grain, about 2 to 10 wt. % of a carbon, and about 1 to 12 wt. % of an oxidation and erosion resistance additive, the method of making refractory shapes utilizing such composition, and the resultant shapes.

Abstract: High purity fused grain and refractory compositions that contain a high purity fused grain made up of 35 to 85 wt. % chromia, 5 to 55 wt. % alumina, and 5 to 45 wt. % magnesia. Burned refractory brick having such a chemistry was found to unexpectedly possess superior resistance to AOD and electric furnace slags.