Patents by Inventor Yoshiyuki Hashimasa

Yoshiyuki Hashimasa 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: 6187259
    Abstract: The object of the present invention is to provide rare-earth system sintered magnets such as R—Fe—B system or R—Co system having excellent magnetic properties, unique configuration of a small size, thin wall thickness and intricate geometry. With the method for preparing the present invention, a granulation of alloy powders can be achieved easily, a chemical reaction between rare-earth system and binder substances can be suppressed, so that the residual oxygen and carbon levels in the sintered products can be reduced. Moreover, by this production method, the flowability and lubricant capability during the forming process can be improved. The dimension accuracy and productivity are also enhanced. A certain type of binder is added to rare-earth alloy powders and kneaded into a slurry state. The slurry is then formed into granulated powders by spray-dryer equipment. The thus granulated powders are molded, and sintered through a powder metallurgy technique.
    Type: Grant
    Filed: March 19, 1997
    Date of Patent: February 13, 2001
    Assignee: Sumitomo Special Metals Co., Ltd.
    Inventors: Osamu Yamashita, Yoshihisa Kishimoto, Wataru Takahashi, Nobushige Hiraishi, Yoshiyuki Hashimasa, Masakazu Ohkita