Portable transmitter for emergency alarm system having watertight enclosure
US4491970A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 30, 1982 |
| Grant date | Jan 1, 1985 |
| Priority date | — |
| Expiry date | Dec 30, 2002 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B2001/3894
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
The present invention provides a small portable radio transmitter unit which can be worn on the wrist or suspended from a neck chain to provide immediate access in the event of an emergency condition and without interfering with the normal day-to-day activities of the wearer. The unit is contained within a watertight housing having a resilient membrane depressible by finger pressure to actuate a button switch within the housing for actuation of the transmitter. The housing is vented to the atmosphere to provide equalization of internal and ambient pressure in a manner providing isolation from water or other liquid entry to thereby maintain a watertight enclosure.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.