The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 02, 1993
Filed:
Sep. 09, 1991
Douglas J Toth, Huntington Beach, CA (US);
Steven J Shankle, Redmond, WA (US);
Eric R Brooks, Mukilteo, WA (US);
Undersea Industries, Inc., Rancho Dominguez, CA (US);
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 sufficiently to fall below a threshold that is sensed by a pressure attached to a valve on the tank.