Patents by Inventor Masanao Hirakawa

Masanao Hirakawa 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: 5172869
    Abstract: A jaw crusher with a pass-through preventing device which prevents a flat plate-shaped object from passing through without being crushed. Also disclosed is a jaw crusher with a tooth plate structure which is capable of effectively crushing a non-rigid object, for example, a lump of asphalt, without causing such an object to stick to the area between a cheek plate and a fixed tooth plate or a movable tooth plate. The jaw crusher comprises a plurality of forks which are provided at the lower end of a crushing space to prevent a plate-shaped object from passing through the crushing space without being crushed, and a fork shaft which is provided with one end of each fork and which is rotatably provided on the crusher body. The movable tooth plate is provided with cutting projections. A plate-shaped object is first broken by the cutting projections and then crushed by intermediate projections.
    Type: Grant
    Filed: May 1, 1992
    Date of Patent: December 22, 1992
    Assignee: Nakayama Iron Works, Ltd.
    Inventors: Tomohiro Kitsukawa, Yoshihiko Isebaba, Kazuhisa Hirano, Masanao Hirakawa