Patents by Inventor Ryohei Hazawa

Ryohei Hazawa 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).

  • Mold for injection molding a thermoplastic part free from sink marks using a void inducing member
    Patent number: 5540581
    Abstract: When injection-molding a molten thermoplastic resin into a molding having different thicknesses, a void inducing member is set in a cavity corresponding to heavy sections. Then gas pressure is applied passing through a gas passageway to a tip end of the void inducing member, thus forming a void nucleus in the resin adjacent to the tip end of the void inducing member. The void nucleus develops to a void by shrinking force of the resin as the molten resin cools.
    Type: Grant
    Filed: May 24, 1995
    Date of Patent: July 30, 1996
    Assignee: Nippon Steel Chemical Co., Ltd.
    Inventors: Hiroshi Aida, Ryohei Hazawa
  • Injection molding method for manufacturing a thermoplastic part free from sink marks using a void inducing member
    Patent number: 5232654
    Abstract: When injection-molding a molten thermoplastic resin into a molding having different thicknesses, a void inducing member is set in a cavity corresponding to heavy sections. Then gas pressure is applied passing through a gas passageway to a tip end of the void inducing member, thus forming a void nucleus in the resin adjacent to the tip end of the void inducing member. The void nucleus develops to a void by shrinking force of the resin as the molten resin cools.
    Type: Grant
    Filed: December 10, 1991
    Date of Patent: August 3, 1993
    Assignee: Nippon Steel Chemical Co., Ltd.
    Inventors: Hiroshi Aida, Ryohei Hazawa