Patents by Inventor Sadayuki Hiragi

Sadayuki Hiragi 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).

  • Intraoffice alternate connection arrangement
    Patent number: 4063043
    Abstract: An intraoffice trunk switching system wherein a connecting path between the called subscriber and the intraoffice trunk is established first; the connecting path between the calling subscriber and the intraoffice trunk to which the called subscriber is connected is then selected so that if no idle channel is available the first connecting path is released and simultaneously therewith the connecting operation between the calling subscriber and the intraoffice trunk is stopped and an idle intraoffice trunk is selected. The connecting path between the called subscriber and the selected intraoffice trunk is established and then the connecting path between the calling subscriber and the selected intraoffice trunk is set to improve the link block ratio of the intraoffice connection.
    Type: Grant
    Filed: June 6, 1975
    Date of Patent: December 13, 1977
    Assignees: Nippon Telegraph and Telephone Public Corporation, Oki Electric Industry Co., Ltd., Nippon Electric Company, Limited, Hitachi, Ltd., Fujitsu Limited
    Inventors: Joji Tashiro, Tadahiko Kawanabe, Noboru Araki, Kazuo Ashihara, Toshio Ando, Sadayuki Hiragi, Kazuo Itoh, Yukio Ozawa, Eiichi Odera, Kosuke Inoue