Vandal-proof communication system
US4518826A · kind A · utility
44Cited by
5References
7Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Dec 22, 1982 |
| Grant date | May 21, 1985 |
| Priority date | — |
| Expiry date | Dec 22, 2002 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04M1/0291
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A touch switch and monitor lamp associated with an intercom station are embedded in a protective wall mounted plate with exposed ends flush with the planar surface of the plate which has openings through which sound is transmitted to or from a folded horn of a transducer having its driver unit spaced rearwardly of the plate and laterally of the openings.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.