Patents by Inventor David K. Walters

David K. Walters 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: 5342531
    Abstract: A lubricant composition comprising a major proportion of polyalkylene glycol of lubricating viscosity and a minor proportion dissolved therein of (a) at least one sulphur-containing antiwear or extreme pressure agent, (b) at least one amine salt of at least one partially esterified monothiophosphoric acid, and (c) at least one amine salt of at least one partially esterified phosphoric acid. Such compositions have improved resistance to wear, oxidative degradation and metallic corrosion.
    Type: Grant
    Filed: May 27, 1993
    Date of Patent: August 30, 1994
    Assignee: Ethyl Petroleum Additives Limited
    Inventors: David K. Walters, Rodney I. Barber
  • Patent number: 5254272
    Abstract: Lubricant compositions especially useful as hydraulic fluids contain a metal-free anti-wear or load-carrying additive containing sulphur and/or phosphorus and an amino succinate ester as corrosion inhibitor. Such compositions are free from heavy metal and have improved environmental acceptability where heavy metals are to be avoided, e.g. in agriculture. The lubricant base stock may be a biodegradable natural oil.
    Type: Grant
    Filed: November 2, 1992
    Date of Patent: October 19, 1993
    Assignee: Ethyl Petroleum Additives Limited
    Inventors: David K. Walters, Arthur S. Thomas
  • Patent number: 5190680
    Abstract: A friction reducing additive composition comprising a long chain succinimide derivative and a long chain amide has superior friction reducing properties, especially in wet brake systems for tractors and other vehicles.
    Type: Grant
    Filed: March 4, 1991
    Date of Patent: March 2, 1993
    Assignee: Ethyl Petroleum Additives Ltd.
    Inventors: John V. Bullen, David K. Walters
  • Patent number: 5126064
    Abstract: Lubricant compositions, especially suitable for limited slip differentials, containing sulphur-containing extreme pressure or anti-wear agents, are improved by incorporation of a substituted succinimide friction modifier. The resulting compositions reduce the level of noise produced during operation of the differential.
    Type: Grant
    Filed: May 17, 1990
    Date of Patent: June 30, 1992
    Assignee: Ethyl Petroleum Additives, Ltd.
    Inventors: Rodney I. Barber, Charles J. Dain, David K. Walters
  • Patent number: 5021176
    Abstract: A friction reducing additive composition comprising a long chain succinimide derivative and a long chain amide has superior friction reducing properties, especially in wet brake systems for tractors and other vehicles.
    Type: Grant
    Filed: March 5, 1990
    Date of Patent: June 4, 1991
    Assignee: Ethyl Petroleum Additives, Limited
    Inventors: John V. Bullen, David K. Walters
  • Patent number: 4305835
    Abstract: A lubricating oil composition for use in the crankcase of an internal combustion engine, having improved resistance to the formation of emulsion-sludge in the area under the engine rocker cover, which contains the combination of an oxyalkylated alkylphenol-formaldehyde condensation product and an oxyalkylated trimethylolalkane.
    Type: Grant
    Filed: December 8, 1980
    Date of Patent: December 15, 1981
    Assignee: Ethyl Corporation
    Inventors: Rodney I. Barber, David K. Walters
  • Patent number: 4305834
    Abstract: A lubricating oil composition for use in the crankcase of an internal combustion engine, having improved resistance to the formation of emulsion-sludge in the area under the engine rocker cover, which contains the combination of an oxyalkylated alkylphenol-formaldehyde condensation product and tetra polyoxyethylene polyoxypropylene derivative of ethylene diamine.
    Type: Grant
    Filed: December 8, 1980
    Date of Patent: December 15, 1981
    Assignee: Ethyl Corporation
    Inventors: Rodney I. Barber, David K. Walters
  • Patent number: RE34459
    Abstract: A friction reducing additive composition comprising a long chain succinimide derivative and a long chain amide has superior friction reducing properties, especially in wet brake systems for tractors and other vehicles.
    Type: Grant
    Filed: July 20, 1992
    Date of Patent: November 30, 1993
    Assignee: Ethyl Petroleum Additives, Limited
    Inventors: John V. Bullen, David K. Walters