Patent search ap:("BELL TELEPHONE LABOR INC") AND inv:"WARD BRENDAN A" Page 1

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发明授权
Subscriber controlled conference circuit 失效
Title translation: 用户控制会议电路

公开(公告)号：US3231678A

公开(公告)日：1966-01-25

申请号：US20476462

申请日：1962-06-25

Applicant: BELL TELEPHONE LABOR INC

Inventor： WARD BRENDAN A , ALFRED ZAROUNI

IPC: H04M3/56

CPC classification number: H04M3/56

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