Polarized telephone system for 3-state and 4-state systems
US8548126B2 · kind B2 · utility
0Cited by
8References
5Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jun 13, 2005 |
| Grant date | Oct 1, 2013 |
| Priority date | — |
| Expiry date | Jul 24, 2030 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04M1/18
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A firefighter's telephone communication system is provided that includes a polarized telephone station that may be connected to either 3-state (detection of normal, open, or call-in) or 4-state (detection of normal, open, short, or call-in) telephone control panel, without the need to alter the telephone station.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.