Low air warning system for scuba divers
US5191317A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 9, 1991 |
| Grant date | Mar 2, 1993 |
| Priority date | — |
| Expiry date | Sep 9, 2011 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T137/2036
- WIPO fieldTransport
- WIPO sectorMechanical engineering
Abstract
A low air warning system for scuba divers in which a pressure switch and an electromagnetic transmitter are positioned at or near the high pressure air supply tank of the scuba diver and a corresponding electromagnetic receiver is positioned on the diver's mask. A plenum extending from the receiver, provides a pair of LED light indicators of two different colors which also oscillate at different frequencies, depending upon the condition of the pressure switch in response to the supply of air in the diver's air supply tank. A unique electromagnetic transmission and receiving system is disclosed which relies upon magnetic induction between a high Q transmitting antenna and a high Q receiving antenna in the form of LC tank circuits. One of the novelties of the present invention is the use of frequency modulation and the use of distinct modulating tone frequencies which produce one or the other of two signals to activate one or the other of two LEDs of different colors and at different activation frequencies. Changes in both the color and frequency of the flashing light virtually assure that the diver cannot ignore a change in the status of his air supply when it has been reduced suffi…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.