Patents by Inventor Stuart Karl Randa

Stuart Karl Randa 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).

  • Fluoropolymer modification of strings for stringed sports equipment and musical instruments
    Patent number: 6835454
    Abstract: The modification of strings for sports equipment and musical instruments and other stringed devices by coating with fluoropolymer coatings to reduce the coefficient of friction of the string surfaces and to reduce the internal friction of the string components among themselves.
    Type: Grant
    Filed: July 14, 2000
    Date of Patent: December 28, 2004
    Inventors: Stuart Karl Randa, James M Fitzgerald
  • High speed extrusion
    Patent number: 5945478
    Abstract: Extrusion rheology of thermoplastic polymer as manifested by surface smoothness is improved by incorporating foam cell nucleating agents into the polymer and extruding the polymer under laminar flow to form unfoamed extrudate.
    Type: Grant
    Filed: June 25, 1997
    Date of Patent: August 31, 1999
    Assignee: E. I. du Pont de Nemours and Company
    Inventors: Marlin Dwight Buckmaster, Stuart Karl Randa
  • Method of forming foamed fluoropolymer composites
    Patent number: 5885494
    Abstract: Fluoropolymer is advantageously foamed by first forming a composite structure of a layer of the fluoropolymer to be foamed and a layer of different material such as a different fluoropolymer not to be foamed, followed by heating the composite structure to the foamable state for the layer of fluoropolymer to be foamed, pressurizing the heated composite structure with supercritical carbon dioxide, rapidly depressurizing the heated composite structure, whereby the foamable layer foams and the other layer foams less or not at all, and cooling the foamed composite structure.
    Type: Grant
    Filed: May 7, 1997
    Date of Patent: March 23, 1999
    Assignee: E. I. du Pont de Nemours and Company
    Inventors: Sundar Kilnagar Venkataraman, Stuart Karl Randa, Peter Dwight Spohn
  • Plenum cable
    Patent number: 5841073
    Abstract: A plenum cable is provided which passes the category 5 requirements, including the UL 910 burn/smoke test, the cable containing at least four twisted pairs of insulated conductors, the insulation of one of the pairs of insulated conductors being foamed polyolefin which is free of flame retardant additive and the insulation of the other three twisted pairs of insulated conductors being fluoropolymer, the cable having a skew between twisted pairs of no greater than 30 nanoseconds.
    Type: Grant
    Filed: September 5, 1996
    Date of Patent: November 24, 1998
    Assignee: E. I. du Pont de Nemours and Company
    Inventors: Stuart Karl Randa, George Martin Pruce
  • Self-foaming fluoropolymer composition
    Patent number: 5726214
    Abstract: Fluoropolymer having unstable end groups is used to form foamed fluoropolymer structures without added blowing agent.
    Type: Grant
    Filed: December 26, 1996
    Date of Patent: March 10, 1998
    Assignee: E. I. du Pont de Nemours and Company
    Inventors: Marlin Dwight Buckmaster, Stuart Karl Randa
  • Two-part nucleating agent system
    Patent number: 5712318
    Abstract: A foam cell nucleating agent that is a combination of sulfonic or phosphonic acid or salt thereof and inorganic salt containing a polyatomic anion yields improved foaming of thermoplastic resins such as polyolefins and melt-fabricable fluoropolymers.
    Type: Grant
    Filed: October 30, 1996
    Date of Patent: January 27, 1998
    Assignee: E. I. Du Pont de Nemours and Company
    Inventors: Marlin Dwight Buckmaster, Donald Leonidas Henry, Stuart Karl Randa
  • High speed extrusion
    Patent number: 5688457
    Abstract: Extrusion theology of thermoplastic polymer as manifested by surface smoothness is improved by incorporating foam cell nucleating agents into the polymer and extruding the polymer under laminar flow to form unfoamed extrudate.
    Type: Grant
    Filed: April 10, 1996
    Date of Patent: November 18, 1997
    Assignee: E. I. Du Pont de Nemours and Company
    Inventors: Marlin Dwight Buckmaster, Donald Leonidas Henry, Stuart Karl Randa