Patents by Inventor Robert A. Covington, Jr.

Robert A. Covington, Jr. 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).

  • Continuous synthesis of chromium dioxide
    Patent number: 4428852
    Abstract: Ferromagnetic chromium dioxide is produced in a continuous operation by feeding a preheated paste of hydrated chromium oxides and additives into a twin screw reactor, reacting at elevated temperature and pressure for a short time while venting oxygen and steam, injecting water near the end of the reaction zone to form a viscous chromium dioxide-water mixture, and cooling while passing through a pressure letdown extruder.
    Type: Grant
    Filed: January 18, 1982
    Date of Patent: January 31, 1984
    Assignee: E. I. Du Pont de Nemours and Company
    Inventors: Robert A. Covington, Jr., Cecil L. Long, David W. Williston
  • In-line coagulation process for fluoroelastomer emulsions
    Patent number: 4408038
    Abstract: In-line continuous coagulation and agglomeration of fluoroelastomers produced by emulsion polymerization permits direct processing of fluoroelastomer latex into mechanical dewatering devices. Coagulant is injected into the fluoroelastomer latex countercurrent and under high pressure atomization and residence time prior to mechanical dewatering is controlled.
    Type: Grant
    Filed: March 29, 1982
    Date of Patent: October 4, 1983
    Assignee: E. I. Du Pont de Nemours & Co.
    Inventors: Robert A. Covington, Jr., Okan M. Ekiner
  • Mechanical dewatering apparatus for elastomer slurries
    Patent number: 4228005
    Abstract: A method is provided for isolating an elastomer from a mixture of the elastomer and water containing up to about 90% by weight water by feeding the mixture into a thermally controlled, vertical separator containing a rotating screw, simultaneously feeding excess water under pressure into the separator, withdrawing concentrated elastomer containing less than about 10% by weight total volatiles (including water) from the metering section of the separator and withdrawing feed water and excess water from a water discharge port located near the upper end of the separator.In addition, apparatus for isolating elastomers from mixtures of elastomers and water is provided.
    Type: Grant
    Filed: June 19, 1978
    Date of Patent: October 14, 1980
    Assignee: E. I. Du Pont de Nemours and Company
    Inventors: Robert A. Covington, Jr., Okan M. Ekiner
  • Mechanical dewatering process for elastomer slurries
    Patent number: 4132845
    Abstract: A method is provided for isolating an elastomer from a mixture of the elastomer and water containing up to about 90% by weight water by feeding the mixture into a thermally controlled, vertical separator containing a rotating screw, simultaneously feeding excess water under pressure into the separator, withdrawing concentrated elastomer containing less than about 10% by weight total volatiles (including water) from the metering section of the separator and withdrawing feed water and excess water from a water discharge port located near the upper end of the separator.In addition, apparatus for isolating elastomers from mixtures of elastomers and water is provided.
    Type: Grant
    Filed: May 27, 1977
    Date of Patent: January 2, 1979
    Assignee: E. I. Du Pont de Nemours and Company
    Inventors: Robert A. Covington, Jr., Okan M. Ekiner