| 发明名称 |
Emergency transfer circuit for use in a communication switching system |
| 摘要 |
An emergency transfer circuit for permitting an operator to extend an emergency-type call via a toll switchboard trunk circuit in the event of malfunction in the switching equipment.
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| 申请公布号 |
US3909545(A) |
申请公布日期 |
1975.09.30 |
| 申请号 |
US19740466429 |
申请日期 |
1974.05.02 |
| 申请人 |
GTE AUTOMATIC ELECTRIC LABORATORIES INCORPORATED |
发明人 |
FUCHS, SIEGFRIED H. |
| 分类号 |
H04M3/12;(IPC1-7):H04M7/06 |
主分类号 |
H04M3/12 |
| 代理机构 |
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代理人 |
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| 主权项 |
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| 地址 |
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