Patents by Inventor Vishnu Sarma Avva

Vishnu Sarma Avva 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).

  • Apparatus and method for forming densified, carbon-carbon composites
    Patent number: 7332112
    Abstract: An apparatus and method for forming a densified carbon-carbon composite. The apparatus includes: a green part molding station for forming a green part; a carbonization station for carbonizing the green part; and an impregnation station for impregnating the carbonized part with a substantially curing by-product free, high carbon yield resin. The impregnation station includes a mold forming a sealed enclosure configured in the shape of the carbonized part for receiving the carbonized part and a vacuum source for evacuating the mold. At least one resin injection port is in the mold and a supply of substantially curing by-product free, high carbon yield resin is connected to the resin injection port for injection into the mold. In the preferred embodiment, the substantially curing by-product free, high carbon yield resin is a cyanate ester having a viscosity of less than about 100 cps at 250° F. and a carbon yield value of greater than about 60 wt. %.
    Type: Grant
    Filed: May 24, 2004
    Date of Patent: February 19, 2008
    Assignee: N.C. A&T State University
    Inventors: Kunigal N. Shivakumar, Vishnu Sarma Avva, Mannur J. Sundaresan, Felix Abali, Anthony Cunningham, Robert L. Sadler
  • Apparatus and method for forming densified, carbon-carbon composites
    Patent number: 6325608
    Abstract: An apparatus and method for forming a densified carbon-carbon composite. The apparatus includes: a green part molding station for forming a green part; a carbonization station for carbonizing the green part; and an impregnation station for impregnating the carbonized part with a substantially curing by-product free, high carbon yield resin. The impregnation station includes a mold forming a sealed enclosure configured in the shape of the carbonized part for receiving the carbonized part and a vacuum source for evacuating the mold. At least one resin injection port is in the mold and a supply of substantially curing by-product free, high carbon yield resin is connected to the resin injection port for injection into the mold. In the preferred embodiment, the substantially curing by-product free, high carbon yield resin is a cyanate ester having a viscosity of less than about 100 cps at 250° F. and a carbon yield value of greater than about 60 wt. %.
    Type: Grant
    Filed: May 17, 1999
    Date of Patent: December 4, 2001
    Assignee: North Carolina A&T State University
    Inventors: Kunigal N. Shivakumar, Vishnu Sarma Avva, Mannur J. Sundaresan, Felix Abali, Anthony Cunningham, Robert L. Sadler