Patents by Inventor Purnachandra Pai

Purnachandra Pai 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: 4773717
    Abstract: Disclosed is a coated article, for example an architectural transparency, or a vehicular transparency, or a reflecting article, as a decorative article. The article has a substrate, e.g., a substantially transparent substrate. The substrate has an optical coating on a surface thereof. The coating is a bilayer dielectric thin film having a thickness corresponding to a constructively interfering function of a wavelength of interest. The bilayer thin film is a metallic layer, which serves as an adhesion layer, with a dielectric atop the metallic layer which is a compound of the metal forming the metallic layer.
    Type: Grant
    Filed: November 3, 1986
    Date of Patent: September 27, 1988
    Assignee: Ovonic Synthetic Materials Co.
    Inventors: Purnachandra Pai, Jun S. Im, John Piner
  • Patent number: 4759993
    Abstract: A coated stainless steel article and a method of preparing the article are disclosed. The coating is a plasma chemical vapor deposited coating, formed from a plasma of nitrous oxide, a silane, and an energy transfer agent (such as He, Ar). The resulting coating is adherent, corrosion resistant, and has a thickness sufficient to mask and cover the features of the stainless steel substrate, and to provide a pitting potential (in 3.5% NaCl) of greater than 600 millivolts, a J.I.S. 8502 (1982) versus a saturated calomel electrode a salt spray test rating in 5% NaCl-0.02% hydrogen peroxide of at least B.
    Type: Grant
    Filed: April 25, 1985
    Date of Patent: July 26, 1988
    Assignee: Ovonic Synthetic Materials Co., Inc.
    Inventors: Purnachandra Pai, Benjamin Chao, Keith Hart, Yasuo Takagi
  • Patent number: 4702955
    Abstract: A coated article, for example an architectural transparency, including a vehicular transparency, or a reflecting article, as a decorative article. The article has a substrate, e.g., a substantially transparent or substantially opaque substrate. The substrate has an optical coating on it, that is a coating having a thin film of an oxide of a transition metal, the thin film having a thickness corresponding to a constructively interfering function of a wavelength of interest. The optical coating, having a thin film of a transition metal, enhances the reflectivity of some wavelengths of the visible portion of the electromagnetic spectrum and the reflectivity of other wavelengths of the visible portion of the electromagnetic spectrum.
    Type: Grant
    Filed: January 27, 1986
    Date of Patent: October 27, 1987
    Assignee: Ovonic Synthetic Materials Company, Inc.
    Inventors: David Allred, Alan Kadin, Purnachandra Pai
  • Patent number: 4159972
    Abstract: A recycling process for flexible polyurethane foam which comprises dissolving the foam in low molecular weight diol, admixing therewith high molecular weight polyol that is suitable for preparation of flexible urethane foam, removing under vacuum low molecular weight diol solvent from the admixture obtained, and recovering the residue which comprises polyol product that may be used to provide new flexible foam with desirable properties including advantageous tear strength.
    Type: Grant
    Filed: October 17, 1977
    Date of Patent: July 3, 1979
    Assignee: Ford Motor Company
    Inventors: Jacob Braslaw, Purnachandra Pai