Patents by Inventor Thomas S. Piwonka

Thomas S. Piwonka has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 5033948
    Abstract: The solid metal to be melted is placed on a support, within an induction coil which is adapted to provide a greater electromagnetic force towards the lower portion of the quantity of metal. When energy is provided to the coil, the metal melts from the top downward, but the concentration of electromagnetic force towards the bottom of the metal causes the liquid metal to retain a cylindrical shape. When most of the metal is melted, the liquid metal passes through an opening in the support. In a preferred embodiment, the coil is movable relative to the quantity of metal, and at the beginning of the melting process only the top portion of the quantity of metal is disposed within the coil. As the quantity of metal melts, the coil is moved downward. The method may also be used for removing impurities from the quantity of metal.
    Type: Grant
    Filed: April 6, 1990
    Date of Patent: July 23, 1991
    Assignee: Sandvik Limited
    Inventors: Nagy H. El-Kaddah, Thomas S. Piwonka, John T. Berry
  • Patent number: 5014769
    Abstract: The solid metal to be melted is placed within an induction coil which is adapted to provide a greater electomagnetic force towards the lower portion of the quantity of metal. The solid metal rests on a support, having an opening therethrough, which is kept at a low temperature relative to the metal as it melts. When energy is provided to the coil, the metal melts from the top downward, but the concentration of electromagnetic force towards the bottom of the metal causes the liquid metal to retain a cylindrical shape. When most of the metal is melted, the liquid metal passes through the opening in the support into a casting mold.
    Type: Grant
    Filed: April 17, 1989
    Date of Patent: May 14, 1991
    Assignee: Inductotherm Corp.
    Inventors: Nagy H. El-Kaddah, Thomas S. Piwonka, John T. Berry
  • Patent number: 4683936
    Abstract: To cast an article, a mold is lowered into a body of molten metal with an open end of the mold facing downwardly so that the molten metal fills a mold cavity. The mold is then withdrawn form the body of molten metal. As the mold is withdrawn, the molten metal in the mold cavity is solidified. During withdrawal of the mold from the body of molten metal, the level of the upper surface of the body of molten metal is maintained substantially constant. The economical production of castings is promoted by simultaneously lowering a plurality of molds into the molten metal and withdrawing them from the molten metal to simultaneously form a plurality of castings. A strengthening agent may be added to the molten metal by dispensing the strengthening agent to form a dispersoid a short distance beneath the surface of the molten metal as the mold is withdrawn from the molten metal.
    Type: Grant
    Filed: May 8, 1986
    Date of Patent: August 4, 1987
    Assignee: TRW Inc.
    Inventors: Michael Cybulsky, Thomas S. Piwonka, Virgil R. Brittain
  • Patent number: 4449567
    Abstract: A plurality of mold wall segments are positioned in a circular array in an adjustable fixture to form a mold assembly. The fixture includes a base with a plurality of upstanding pin members. Two of the pin members engage the bottom portion of each mold wall segment. Each pin member is eccentrically mounted on a disc. By rotating the discs relative to their base, the mold wall segments may be moved inward or outward. This movement varies the diameter of the lower portion of the mold assembly. The pin members have threaded end portions which enable the pin members to be moved along their upstanding central axes. This movement varies the height of the lower portion of the mold assembly. In addition, the fixture includes a plurality of radially extending adjusting rods, each rod engages a radially inner side surface of a mold segment.
    Type: Grant
    Filed: August 6, 1979
    Date of Patent: May 22, 1984
    Assignee: TRW Inc.
    Inventors: William S. Blazek, Thomas S. Piwonka
  • Patent number: 4170256
    Abstract: A segmented mold assembly is utilized to cast a turbine engine component having a relatively heavy hub from which relatively light vanes project. The mold assembly includes a plurality of sections which are formed of a ceramic mold material and are interconnected at flange joints. The mold sections are advantageously formed by repetitively dipping patterns in a slurry of liquid ceramic mold material to form wet coatings on the patterns. These wet coatings are dried and separated from the patterns to form the mold sections. The mold sections which are used to cast the vanes retard the removal of heat from the vanes to provide time for the hub to solidify. This can be accomplished by using relatively thick walled mold sections to form the mold cavities in which vanes are cast and relatively thin walled mold sections to form the cavity in which the hub is cast.
    Type: Grant
    Filed: August 29, 1977
    Date of Patent: October 9, 1979
    Assignee: TRW Inc.
    Inventors: William S. Blazek, Thomas S. Piwonka, James D. Jackson, Philip N. Atanmo
  • Patent number: 4066116
    Abstract: A segmented mold assembly is utilized to cast a turbine engine component having an annular inner wall and an annular outer wall which are interconnected by a plurality of struts or vanes. The mold assembly includes a plurality of sections which are formed of a ceramic mold material and are interconnected at flange joints. A pair of mold sections are advantageously formed simultaneously by repetitively dipping a single pattern in a slurry of liquid ceramic mold material to form a wet coating on the pattern. This wet coating of ceramic mold material is then dried. After a covering of the desired thickness has been built up by repetitively dipping and drying the coatings on the wax pattern, the wax pattern is destroyed. To facilitate separating the mold sections after destroying the wax pattern, at least some of the wet coatings are wiped away in an area between portions of the wet coatings which will eventually form the mold sections.
    Type: Grant
    Filed: January 29, 1976
    Date of Patent: January 3, 1978
    Assignee: TRW Inc.
    Inventors: William S. Blazek, Thomas S. Piwonka, James D. Jackson, Philip N. Atanmo