Abstract: The present system is directed to both a method and apparatus for manufacture of teeth for use in drill bits. The desired tooth is formed by a hard carbide, a protective disc placed on the end of the support, the joinder being accomplished by a braze metal layer. The process contemplates positioning the disc in a matching receptacle within the head of a molding apparatus wherein the head and cavity of the head are exposed to the terminus of several coolant flow lines through the head so that the disc is brought into contact with flowing coolant. The fluid coolant is delivered by a compressor at elevated pressure and is a flow of cooled gas after dehydration. Rapid flow of heat into cooled support at the base prevent deterioration of the diamond layer while allowing use of higher temperature braze metals.
Abstract: Disclosed is a high-frequency heating apparatus including an elongated chamber in which a plurality of rocker arms are introduced, each of the rocker arms being attached with a chip and brazing filler such as a copper wax, a high-frequency brazing coil for high-frequency heating a designated part of each rocker arm in the chamber to braze the chip to the rocker arm, a high-frequency temperature-holding coil for holding the temperature of the rocker arm constant, and a nitrogen gas supplying device for keeping the chamber filled with a nitrogenous atmosphere during the high-frequency heating.
Abstract: Induction heating is utilized to heat polymer matrix composites containing electrically conductive fibers. This is accomplished with an apparatus having a mandrel for supporting a composite workpiece and a helical induction coil disposed around the mandrel. The mandrel, workpiece and induction coil are disposed in an autoclave. The mandrel is a hollow, porous member having a port formed therein which is connected to a vacuum. A vacuum bag is hermetically sealed on the mandrel so as to define an enclosure over the workpiece. A power source is connected to the induction coil and, when activated, causes the coil to generate an oscillating magnetic field lying along the longitudinal axis of the mandrel. The magnetic field induces heat-generating eddy currents in the fibers of the workpiece which are oriented orthogonally to the magnetic field.
Abstract: Induction heating is utilized to heat polymer matrix composite fiber strands containing electrically conductive fibers. This is accomplished with an apparatus having a helical induction coil and a matching helical guide tube situated adjacent to the induction coil. Composite fiber strands are drawn through the guide tube which is made of a non-electrically conductive, nonmagnetic material. Electrically conductive rollers, positioned next to the entrance and exit of the guide tube, form an electrical circuit with the electrically conductive fibers. This permits currents to be induced in the fibers when the coil is activated, thereby heating the fiber composites. The guide tube can be thermally insulated and flushed with an inert purge gas. Alternatively, the guide tube can be made of an electrically conductive or ferromagnetic material so that heat producing currents are induced in the guide tube, and the composite fiber strands are heated by conduction.
Abstract: A mill roll having a pair of thick-walled refractory rollers, some having chambers therein the rollers to be heated to incandescent temperatures is disclosed.