Patents by Inventor Yosuharu Yokoyama

Yosuharu Yokoyama 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: 7399736
    Abstract: An engine oil composition that has lower viscosity then the lowest viscosity grade specified by the current standard (SAE (Society of Automotive Engineers) viscosity classification) and achieves excellent abrasion resistance under conditions of high temperature and high shear rate without an increase in the amount of anti-abrasion agent, said engine oil composition characterized by the following facts: the engine oil composition contains 0.02-0.12 mass % of zinc dithiophosphate, measured in the phosphorous amount based on the total weight of the composition, in a base oil compromised of a mineral oil and/or a synthetic oil; (1) the high-temperature high-shear viscosity at 150° C. and at a shear rate of 1×106 s?1 is less than 2.6 mPa·s; (2) the engine oil composition satisfies the following equation: kinematic ? ? viscosity ? ? at ? ? 100 ? ? ? C .
    Type: Grant
    Filed: March 25, 2005
    Date of Patent: July 15, 2008
    Assignee: Tonengeneral Sekiyu K.K.
    Inventors: Miyoshi Marumo, Yosuharu Yokoyama, Hiroyuki Iwasaki
  • Publication number: 20050221998
    Abstract: An engine oil composition that has lower viscosity then the lowest viscosity grade specified by the current standard (SAE (Society of Automotive Engineers) viscosity classification) and achieves excellent abrasion resistance under conditions of high temperature and high shear rate without an increase in the amount of anti-abrasion agent, said engine oil composition characterized by the following facts: the engine oil composition contains 0.02-0.12 mass % of zinc dithiophosphate, measured in the phosphorous amount based on the total weight of the composition, in a base oil compromised of a mineral oil and/or a synthetic oil; (1) the high-temperature high-shear viscosity at 150° C. and at a shear rate of 1×106 s?1 is less than 2.6 mPa.
    Type: Application
    Filed: March 25, 2005
    Publication date: October 6, 2005
    Inventors: Miyoshi Marumo, Yosuharu Yokoyama, Hiroyuki Iwasaki