Patents Assigned to Hiraoka Giken Kogyo Co., Ltd.
  • Apparatus for molding a concrete pipe
    Patent number: 4360331
    Abstract: An apparatus for molding a concrete pipe in which a belt conveyor runs parallel to the axis of a molding flask and is adapted to longitudinally move in the molding flask within the range between both ends of the molding flask. The belt conveyor is subjected to intermittent longitudinal movement at a fixed traveling distance in response to a prescribed degree of compactedness of concrete attained in each position where the belt conveyor stops.
    Type: Grant
    Filed: May 8, 1981
    Date of Patent: November 23, 1982
    Assignee: Hiraoka Giken Kogyo Co., Ltd.
    Inventor: Kunizo Hiraoka
  • Process for molding a concrete pipe
    Patent number: 4311632
    Abstract: A process of molding a concrete pipe is proposed. The attainment of a predetermined degree of compactedness of fresh concrete is electrically detected through a pressing roller by which the fresh concrete is compacted in a molding flask. When a predetermined degree of compactedness of concrete is attained in one place within the molding flask, a belt conveyor for feeding the molding flask with fresh concrete is automatically moved to the next place.
    Type: Grant
    Filed: June 16, 1980
    Date of Patent: January 19, 1982
    Assignee: Hiraoka Giken Kogyo Co., Ltd.
    Inventor: Kunizo Hiraoka