公开(公告)号：US4280022A

公开(公告)日：1981-07-21

申请号：US6519

申请日：1979-01-25

申请人： Koichi Sekiguchi ,  Hikaru Takematsu ,  Kazutada Tatsukura

发明人： Koichi Sekiguchi ,  Hikaru Takematsu ,  Kazutada Tatsukura

IPC分类号： H04M9/00 ,  H04Q5/20

CPC分类号： H04M9/007

摘要： A key telephone system adapted to selectively connect a plurality of key telephone sets to a plurality of CO lines through a key service unit and pluralities of talking lines and control lines and provided with a calling device in at least one of the key telephone sets, in which automatic holding of the CO line is enabled upon depression of a calling key. In case of transferring the incoming call from a receiving key telephone set to a called one of the other key telephone set, depression of the individual calling switch automatically starts calling of the called key telephone set and enables the called party to recognize the incoming call by means of lamp indication and answer the calling CO line. The number of cable conductors interconnecting the key service unit and the key telephone sets is effectively reduced.

摘要翻译： 一种密钥电话系统，适于通过密钥服务单元和多条通话线路和控制线路将多个密钥电话机选择性地连接到多条CO线路，并且在至少一个密钥电话机中设置有呼叫装置， 在按下呼叫键时启用CO线路的自动保持。 在将来电从接收密钥电话机转移到另一个密钥电话机中的被叫方的情况下，单独呼叫交换机的按下自动开始呼叫被叫密钥电话机，并使得被叫方能够通过 指示灯指示并接听呼叫CO线路。 将密钥服务单元和密钥电话机互连的电缆导体的数量有效地减少。