Patents by Inventor Mineo Yoshizaki

Mineo Yoshizaki 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).

  • Private automatic branch exchange having two exchange units
    Patent number: 4136264
    Abstract: A private automatic branch exchange (PABX) system having first and second exchange units each including a marker and a switch frame wherein the connection between a central office called trunk belonging to the first exchange unit and a subscriber belonging to the first exchange unit is made through the switch frame of the first exchange unit by activating only the marker of the first exchange unit from a position circuit, and the connection between the central office called trunk and a subscriber belonging to the second exchange unit is made through the switch frame of the first exchange unit, an interunit trunk and the switch frame of the second exchange unit by sequentially activating the marker of the first exchange unit and the marker of the second exchange unit from the position circuit.
    Type: Grant
    Filed: April 18, 1977
    Date of Patent: January 23, 1979
    Assignee: Hitachi, Ltd.
    Inventor: Mineo Yoshizaki