Abstract: A method and apparatus for arc welding particularly regarding a pulse arc welding machine comprising a welding power source having an output characteristic control circuit, an overload protection circuit, a driving circuit, and a main power circuit, and a wire feeding unit having a wire feeding control circuit, a motor driving circuit and a wire feed motor. The output characteristic control circuit comprises a welding arc autoregulating control system which provides the power source with a multi-segmental and moving output characteristic with varying slope, a circuit for connecting arbitrary number of output characteristic segments with arbitrary or varying slope, and a scanning circuit for obtaining the output characteristic segment with varying slope. A particular use of the control system is in an easy to operate autoregulating controlled GMA welding machine with one-knob control of wire feed rate without having to adjust the other welding parameters.

Abstract: A tool holder of the two-jaw type is provided which has the centering accuracy and gripping power of a three-jaw geared chuck. The tool holder includes a body having ways formed by a polygonal passageway which is perpendicular to the central axis of the tool holder body. The jaw mechanism includes a differential screw which mates, on one end, with the body of the tool holder and, on the other end, with a pair of anvil pieces. The face of the differential screw and the anvil pieces move toward and away from the central axis of the tool holder along the ways formed by the polygonal passageway and provide the tool-gripping means.

Abstract: A process for extractive metallurgy of metal sulfides, in particular copper sulfide ores, in which a metal sulfide mineral feed material is cocurrently oxidized in an aqueous cupric chloride solution in the presence of an oxidant to form a slurry containing a metal hydroxide precipitate; the slurry is leached with an acid; the leach solution is extracted with an organic extractant; the organic extractant is stripped with an aqueous stripping medium; and the copper is electrowon from the aqueous stripping medium. The large amount of acid required for the oxidation reaction is provided by the formation of the metal hydroxide precipitate.

Abstract: Process and apparatus for the compression release retarding of a multi-cylinder four cycle internal combustion engine are provided. The process provides a compression release event and a bleeder event or a second compression releaser event for each engine cylinder during each complete engine cycle while employing only one intake valve opening per engine cycle. In accordance with one embodiment of the invention the normal motion of the exhaust valve is disabled and replaced with an opening of the exhaust valve at about the top dead center position of the engine piston following the compression stroke; maintaining the exhaust valve in the open position during the expansion stroke; partially closing the exhaust valve during the exhaust stroke; and fully closing the exhaust valve during the intake stroke.

Abstract: Process and apparatus for the compression release retarding of a multi-cylinder four cycle internal combustion engine are provided. The process provides a compression release event for each cylinder during each revolution of the engine crankshaft. In accordance with the process, the normal motion of the exhaust and intake valves is inhibited and the exhaust valves are opened briefly at each time the engine piston approaches the top dead center position. The intake valves are opened after each opening of the exhaust valves. The apparatus includes hydraulic means driven by the engine pushtubes which produce a timed hydraulic pulse adapted to open the exhaust and intake valves at the proper time. Hydraulically actuated means are provided to disable the valve crosshead or rocker arm so as to inhibit the normal motion of the valves. Alternatively, timed signals from an electronic controller actuate solenoid valves to control a hydraulic pulse which opens the valves.

Abstract: In an extensible arm having a reticular lattice structure with a polygonal cross-section, particularly for space modules or vehicles, each longitudinal side of the lattice structure includes first and second kinematic pantograph chains each constituted by a plurality of rods articulated together so as to define a series of aligned X-shaped elements. The rods of the second kinematic chain are shorter than the rods of the first kinematic chain, and the articulations between the X-shaped elements of the second kinematic chain located on one side of the latter coincide with the articulations between the X-shaped elements of the first kinematic chain located on the same side.

Abstract: A process for melting a ferrous burden comprising scrap iron, scrap steel, pig iron, direct reduced iron or mixtures thereof without the use of coke is provided. Air or enriched air as a primary oxidant is preheated and together with fuel is combusted to form a reducing atmosphere in a shaft furnace or forehearth which melts the ferrous burden in the melting zone of the shaft furnace. The reducing atmosphere leaving the melting zone of the shaft furnace is further combusted with a secondary oxidant in the preheating zone of the shaft furnace. The top gas from the preheating zone of the shaft furnace is combusted with a tertiary oxidant to provide a heated flue gas to preheat the primary oxidant. Optionally, the heat remaining in the flue gas after preheating the primary oxidant may be recovered in a waste heat recovery device.

Abstract: A compression release engine retarder for a multicylinder four-stroke cycle engine is disclosed. The retarder incorporates an hydraulic pulse generator including a multichamber positive displacement pump of the piston and cylinder or gear pump type which is positively driven at engine speed or at half engine speed in synchronism with the engine crank shaft. Means are provided to adjust the timing of the hydraulic pulses so as to control precisely the opening of the engine exhaust valves and to maximize the compression release retarding power developed by the engine. Additional means are provided to control the timing of the hydraulic pulses in response to the boost pressure in the engine inlet manifold produced by the engine turbocharger.

Abstract: A composition for use in fluidizing accumulated pit scrap in ingot soaking pits is provided which contains from about 38 to about 56 wt. % SiO.sub.2, from about 2 to about 4 wt. % C, and from about 38 to about 56 wt. % FeO. A method is also provided according to which an effective amount of the above composition is added to the pit and the pit maintained at a temperature and for a time sufficient to fluidize the accumulated pit scrap. The fluidized pit scrap is then removed by drainage or mechanical means.

Abstract: The present invention relates to tubular connections for application to heavy wall, high performance casing in high pressure, critical service oil and gas wells. A threaded and coupled tubular connection is provided which comprises a male member and a female member having engageable threads disposed on respective first and second substantially matching tapers of about 1.750 inches per foot on the diameter. This taper provides increased female member wall thickness at the narrow end of the female taper; increases the perfect thread length; provides deeper stabbing of the male member into the female member; reduces leakage path clearances; and reduces the male member-in-female member position tolerance. The taper tolerances of the male and female thread tapers are staggered to provide a lower taper on the male member and a higher taper on the female member which results in an advantageous taper mismatch insuring sealing and interference within the made-up connection adjacent the narrow end of the male member.

Abstract: An apparatus and method is provided simultaneously to quench a tubular on the inside and outside surfaces during horizontal axial movement of the heated tubular into the apparatus. The apparatus comprises a generally cylindrical frame carrying two external and internal quench heads mounted 180.degree. apart on the cylindrical frame. The cylindrical frame is mounted for oscillatory motion about the axis of the frame through an angle of 180.degree.. A first heated tubular is delivered to the apparatus for simultaneous inside and outside quenching while the cylindrical frame is in a first position. Thereafter, the cylindrical frame and the first tubular is oscillated through 180.degree. to the second position where the first tubular may be withdrawn from the apparatus. In its second position, the second inside and outside quenching heads are in registry with the heating furnace so that a second tubular may be quenched while the first tubular is being withdrawn from the apparatus.

Abstract: An improved engine retarder of the compression release type in which the exhaust valves are opened near the end of the compression stroke of the engine by a slave piston hydraulically interconnected with a master piston driven by an existing pushtube is provided. The improved engine retarder includes a second master piston interconnected hydraulically in parallel with the first master piston and driven by a separate existing pushtube whereby the timing of the compression release event may be regulated and the stress on the engine pushtubes may be reduced.

Abstract: An improved method and apparatus for a compression release engine retarder is disclosed. The method and apparatus are used in conjuction with a supercharged internal combustion engine fitted with a compression release engine retarder and a supercharger employing a divided volute exhaust gas turbine. A diverter valve is located between the exhaust manifold of the engine and the exhaust gas turbine. Upon actuation of the compression release engine retarder, all of the exhaust gas (or air) passing through the exhaust manifold is diverted to the portion of the divided volute of the turbine which is closest to the turbine wheel flange and, within that portion to the divided volute, to the region closest to the center of rotation of the turbine wheel.

Abstract: An improved compression release engine braking system is provided for internal combustion engines having two exhaust valves associated with each cylinder. The slave piston of the compression release brake is relocated so as to register with one of the two exhaust valves and the crosshead assembly is modified so that actuation of the exhaust valve rocker arms will open both exhaust valves in the normal manner during the fueling mode of engine operation while the slave piston of the compression release brake will open only one of the exhaust valves during the engine braking mode of engine operation.

Abstract: An hydraulic slave piston return mechanism is provided for an engine retarder of the compression relief type. The mechanism senses the position of the slave piston at the time when the engine exhaust valve has been opened. At this point, the hydraulic pressure on the slave piston is equalized by opening a passageway through the slave piston to an accumulator whereupon the engine exhaust valve spring immediately closes the exhaust valve. Thereafter, the accumulator returns the hydraulic fluid to the hydraulic circuit. The mechanism assures that the exhaust valve opened near the end of the compression stroke to produce the desired engine retarding effect is closed prior to the end of the expansion stroke without affecting the retarding horsepower produced by the engine retarder or the normal functioning of the exhaust valve during the exhaust stroke of the engine.

Abstract: A burner for smelting metal-bearing sulfide ores or concentrates by means of an oxygen-rich gas is disclosed. The oxygen-rich gas is introduced into a chamber so as to aspirate or eject the metal-bearing sulfide ore or concentrate. The oxygen-rich gas and sulfide concentrate are intimately admixed in a cylindrical mixing chamber and then jetted into the heated atmosphere of a smelting furnace.

Abstract: An apparatus and method is provided simultaneously to quench a tubular on the inside and outside surfaces during horizontal axial movement of the heated tubular into the apparatus. The apparatus comprises a generally cylindrical frame carrying two external and internal quench heads mounted 180.degree. apart on the cylindrical frame. The cylindrical frame is mounted for oscillatory motion about the axis of the frame through an angle of 180.degree.. A first heated tubular is delivered to the apparatus for simultaneous inside and outside quenching while the cylindrical frame is in a first position. Thereafter, the cylindrical frame and the first tubular is oscillated through 180.degree. to the second position where the first tubular may be withdrawn from the apparatus. In its second position, the second inside and outside quenching heads are in registry with the heating furnace so that a second tubular may be quenched while the first tubular is being withdrawn from the apparatus.

Abstract: A separator for liquids, such as oil and water, is provided. The separator comprises a tangentially-fed, cylindrical vortex generating chamber which communicates axially with a conical accelerating chamber so as to form an axially disposed vortex of the lower density liquid surrounded by the higher density liquid. Both liquids flow generally downwardly in a helical flow pattern and leave the liquid separator by gravity, the lower density liquid flowing freely through an axially disposed vortex finding tube. The axially disposed vortex finding tube may be adjusted in a plane normal to the axis of the accelerating chamber as well as in the direction of the axis of the accelerating chamber. Additionally, the vortex finding tube may contain a flexible section to permit oscillation of the mouth of the vortex finding tube in a plane normal to the axis of the accelerating chamber.

Abstract: An hydraulic reset mechanism is provided for an engine retarder of the compression relief type. The mechanism senses the force required to hold open an exhaust valve. When this force has decreased substantially from the force required to open the exhaust valve initially, a valve is opened in the hydraulic system to release the hydraulic pressure and permit the exhaust valve to close. The mechanism assures that the engine exhaust valves are closed, or substantially closed, prior to the normal opening of the exhaust valves at the end of the power stroke of the engine without affecting the retarding horsepower produced by the engine brake.

Abstract: Hydro-mechanical brake timing means are provided to control the timing of an engine braking system of the gas compression type for an internal combustion engine wherein the engine braking system includes a hydro-mechanical mechanism which opens the exhaust valve near the top of the compression stroke of the engine so that the energy absorbed by the engine during the compression stroke is not returned to the engine during the expansion stroke. In accordance with the present invention, hydro-mechanical means are provided in the exhaust valve actuating mechanism whereby the clearance in that mechanism is reduced to a value which maximizes the retarding power developed by the engine whenever the engine brake is activated.