公开(公告)号：US3920922A

公开(公告)日：1975-11-18

申请号：US38655073

申请日：1973-08-08

申请人： HITACHI LTD

发明人： NISHIGORI SHOGO ,  MOCHIZUKI KENZI

IPC分类号： H04M3/54 ,  H04Q3/54 ,  H04Q3/555 ,  H04Q3/64 ,  H04Q3/76 ,  H04Q3/10

CPC分类号： H04Q3/54

摘要： A terminal hunting system for automatic telephone switching, in which, in the event that, of a plurality of subscribers'' numbers combined into a group including a pilot number, the pilot number is dialed and found to be busy, one of the idle numbers in the group is seized in such a manner that if the common control device receives the busy pilot number from the register as a called number, it sends a signal to the register and resets itself, while the register changes the called number to another number in the group thereby to energize the common control device again. This process is repeated until an idle number is found. The above-mentioned arrangement eliminates the necessity of the number group and the terminal hunting unit required in the conventional system.