Patents by Inventor Hiroyuki Hamamura

Hiroyuki Hamamura 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: 4790391
    Abstract: An air-pressure impact type drilling method and an apparatus for the same in which a piston of an air hammer drill is moved up and down by pressure air to produce impact energy and the impact energy of the piston is used to give impact vibrations repetitively to a drill bit. In the air-pressure impact type drilling method and the apparatus for the same, the air hammer drill is operated by the pressure air to be supplied from the ground, the air that has already been used for operation of the air hammer drill is exhausted onto the ground through an air exhaust pipe provided in a drilling pipe and communicating with an air exhaust passage formed in the air hammer drill, and substances cut out by the air hammer drill together with muddy water within the trench are discharged by means of a reverse circulation system while drilling on through the earth.
    Type: Grant
    Filed: September 24, 1986
    Date of Patent: December 13, 1988
    Assignee: Tone Boring Co., Ltd.
    Inventors: Hiroyuki Hamamura, Hiroyuki Kawasaki, Taro Watanabe